Matching Items (106)
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The mutual inhibition between synthetic gene circuits and cell growth produces growth feedback in the host-circuit system. Previous studies have demonstrated that the growth feedback has an marked impact on the molecular dynamics of the host-circuit system. However, the complexity of the growth feedback effect is not fully understood. A

The mutual inhibition between synthetic gene circuits and cell growth produces growth feedback in the host-circuit system. Previous studies have demonstrated that the growth feedback has an marked impact on the molecular dynamics of the host-circuit system. However, the complexity of the growth feedback effect is not fully understood. A theoretical framework was developed to study the dynamics of the coupling between growth feedback and synthetic gene circuits. The study’s results reveal three major points about the impact of growth feedback. First, a nonlinear emergent behavior mediated by growth feedback. The unexpected behavior depends on the dynamic ribosome allocation between gene circuit expression and host cell growth. Second, the emergence and loss of unexpected qualitative states on the host-circuit system generated by ultrasensitive growth feedback. Third, the growth feedback-induced cooperativity behavior in synthetic gene modules competing for resources. In addition, growth feedback attenuated the winner-takes-all rules on resource competition between the two self-activating modules. These results demonstrate that growth feedback plays an important role in the host-circuit system’s molecular dynamics. Characterizing general principles from the effect of growth facilitates the ability to minimize or even harness unexpected gene expression behaviors derived from the effect of growth feedback.
ContributorsMelendez-Alvarez, Juan Ramon (Author) / Tian, Xiaojun (Thesis advisor) / Wang, Xiao (Committee member) / Kuang, Yang (Committee member) / Arizona State University (Publisher)
Created2022
Description

Existing research has shown that both ethnic discrimination and household wealth can shape child well-being and development. However, little work examines ethnic discrimination and its relation to income in predicting childhood health globally. This study explores two possible explanations for disparities in infant mortality between ethnic groups across countries worldwide.

Existing research has shown that both ethnic discrimination and household wealth can shape child well-being and development. However, little work examines ethnic discrimination and its relation to income in predicting childhood health globally. This study explores two possible explanations for disparities in infant mortality between ethnic groups across countries worldwide. The first is an explanation based on wealth differentials across ethnic groups. The second is the impact of forms of ethnic discrimination such as past lethal violence or forced labor experienced by the group. This study examines the correlation between ethnic discrimination and infant mortality using household wealth as a covariate. Analyses focused on 266 ethnicities in 40 low- and middle-income countries globally, drawing on infant mortality data from Demographic and Health Surveys and data on ethnic discrimination compiled by the Inclusive Human Learning Lab at Arizona State University. Findings without the inclusion of household wealth show that ethnic groups that predominantly spoke the state language had significantly lower rates of infant mortality. However, this trend disappears when income is added as a covariate. No other measures of discrimination or privilege were associated with infant mortality. Across all analyses, the wealth of the ethnic group was a significant predictor of infant mortality. Future studies should examine whether these trends persist in high-income countries, and whether the general lack of association of discrimination and privilege variables with infant mortality is influenced by how the variables were coded.

ContributorsUn, Anthony (Author) / Hruschka, Daniel (Thesis director) / Drake, Alexandria (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / School of Human Evolution & Social Change (Contributor)
Created2023-05
Description

For African countries during the 1960s and 70s, decolonization marked the first step in a slow crawl toward complete independence. For Western powers and the Soviet Union, however, decolonization presented an opportunity to exert new influence over countries in desperate need of aid, investment, experts, and trade. Amidst the backdro

For African countries during the 1960s and 70s, decolonization marked the first step in a slow crawl toward complete independence. For Western powers and the Soviet Union, however, decolonization presented an opportunity to exert new influence over countries in desperate need of aid, investment, experts, and trade. Amidst the backdrop of increasing Cold War tensions, the US and USSR used foreign aid to pressure development according to either capitalist or Marxist agendas. Thus, sub-Saharan Africa became a battleground of proxy wars and neocolonialism. The Cold War superpowers would back opposing regimes in Angola and prop up, oust, or assassinate leaders in Ghana, Democratic Republic of the Congo, and Tanzania. This disrupted natural political development and created instability and violence, which was compounded by the arrival of the AIDS epidemic in the mid-1980s. AIDS ravaged African societies and destroyed the remaining fibers of leadership. The disease illuminated harsh historical realities as it spread among the conflict-stricken countries of sub-Saharan Africa. The goal of this thesis is to analyze the motivations behind US and USSR foreign aid during the Cold War, understand how their involvement halted the natural progression of pan-Africanism and leadership in newly-independent African countries, and link the resulting violence to the devastation of the AIDS crisis twenty years later. It begins with a look at European colonization in sub-Saharan Africa and traces the legacy of western influence in the region. The paper will then analyze specific examples of the consequences of historical interference, such as in the Angolan Civil War, the Congo Crisis, and the Rwandan genocide. It will introduce the AIDS crisis—coincident with major civil conflict and the end of the Cold War—and reveal the foreign aid response of the international community in the late 1990s and early 2000s, once Cold War-era pressures were gone. Through realizing the continued impact and spread of HIV/AIDS, the objective of this paper is to present a comprehensive view of the modern-day consequences of historical interference.

ContributorsStaker, Gabrielle (Author) / Niebuhr, Robert (Thesis director) / Hruschka, Daniel (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / School of Human Evolution & Social Change (Contributor)
Created2023-05
Description

The electronic dance music (EDM) rave community prides itself in fostering an all- accepting subculture for people to unite in style, song, and dance. Based on the principles of Peace, Love, Unity, and Respect (PLUR), rave events have unique and colorful themes, bass levels you can feel in your heart,

The electronic dance music (EDM) rave community prides itself in fostering an all- accepting subculture for people to unite in style, song, and dance. Based on the principles of Peace, Love, Unity, and Respect (PLUR), rave events have unique and colorful themes, bass levels you can feel in your heart, bright and invigorating laser light shows, and in many cases, a heavy presence of both legal and illegal drug use. Because of the association with illegal substances, open discussions regarding drug presence, use, and harm reduction have been stigmatized and limited in the rave community. This study aims to evaluate the current level of knowledge and attitudes regarding drug presence and harm reduction among “ravers.” All participants were required to be of 18 years of age or older and have attended at least 1 EDM event in the past 5 years. The study involved two stages: (1) collecting qualitative data through in person, phone call, or Zoom interviews (n=14), and (2) collecting quantitative data through closed-ended, anonymous surveys via QuestionPro (n=64). The results indicate that a significant portion of participants in both stages express a desire for easily accessible harm reduction information and increased measures prior to and at EDM events. Starting an open dialogue about drug use and harm reduction efforts within this subculture could help create a safer environment and reduce the negative consequences of drug use.

ContributorsOrillo, Rebecca Marie (Author) / Hruschka, Daniel (Thesis director) / Olive, Foster (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2023-05
Description

The term “Iraqi American” defines any person of Iraqi origin who is residing in the United States. From 1960 until 2014, Iraq experienced numerous armed conflicts and international sanctions. As a result, a great surge of Iraqis migrated out of the country to seek refuge elsewhere. The United States alone

The term “Iraqi American” defines any person of Iraqi origin who is residing in the United States. From 1960 until 2014, Iraq experienced numerous armed conflicts and international sanctions. As a result, a great surge of Iraqis migrated out of the country to seek refuge elsewhere. The United States alone currently houses about 400,000+ persons of Iraqi descent, many of whom identify as its citizens. Despite that, Iraqi Americans remain severely understudied. Therefore, this study aims to understand the cultural barriers Iraqi American women face while seeking healthcare in the United States, and how these barriers can impact their behaviors. I collected data via semi-structured interviews with eight Iraqi American women. In this study, I identified five major themes that contributed to women’s healthcare seeking behaviors: societal/familial pressures, staying “pure,” shame associated with performing medical procedures, taboo surrounding discussions of female health conditions, and issues regarding being in the presence of male doctors. Many of these themes involved cultural stigmas and pointed to potential pathways to destigmatize women’s healthcare in the community. This study acts as an initiative to understanding Iraqi Americans better and lays groundwork for further research.

ContributorsRahee, Hajer (Author) / Hruschka, Daniel (Thesis director) / Drake, Alexandria (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / School of Human Evolution & Social Change (Contributor)
Created2023-05
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Contact tracing was deployed widely during the COVID-19 pandemic to attempt to stop the spread of SARS Co-V-2. This dissertation investigates the research on contact tracing from a scientometric perspective and looks qualitatively at how case investigators and contact tracers conducted public health practice during the pandemic. Through

Contact tracing was deployed widely during the COVID-19 pandemic to attempt to stop the spread of SARS Co-V-2. This dissertation investigates the research on contact tracing from a scientometric perspective and looks qualitatively at how case investigators and contact tracers conducted public health practice during the pandemic. Through approaching the public health practice of contact tracing from both a broad, top-down angle, and an on the ground experiential approach, this dissertation provides insight into the issues facing contact tracing as a public health tool.
ContributorsWhite, Alexandra C. (Author) / Jehn, Megan (Thesis advisor) / Hruschka, Daniel (Committee member) / Gaughan, Monica (Committee member) / Arizona State University (Publisher)
Created2022
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The representation of a patient’s characteristics as the parameters of a model is a key component in many studies of personalized medicine, where the underlying mathematical models are used to describe, explain, and forecast the course of treatment. In this context, clinical observations form the bridge between the mathematical frameworks

The representation of a patient’s characteristics as the parameters of a model is a key component in many studies of personalized medicine, where the underlying mathematical models are used to describe, explain, and forecast the course of treatment. In this context, clinical observations form the bridge between the mathematical frameworks and applications. However, the formulation and theoretical studies of the models and the clinical studies are often not completely compatible, which is one of the main obstacles in the application of mathematical models in practice. The goal of my study is to extend a mathematical framework to model prostate cancer based mainly on the concept of cell-quota within an evolutionary framework and to study the relevant aspects for the model to gain useful insights in practice. Specifically, the first aim is to construct a mathematical model that can explain and predict the observed clinical data under various treatment combinations. The second aim is to find a fundamental model structure that can capture the dynamics of cancer progression within a realistic set of data. Finally, relevant clinical aspects such as how the patient's parameters change over the course of treatment and how to incorporate treatment optimization within a framework of uncertainty quantification, will be examined to construct a useful framework in practice.
ContributorsPhan, Tin (Author) / Kuang, Yang (Thesis advisor) / Kostelich, Eric J (Committee member) / Crook, Sharon (Committee member) / Maley, Carlo (Committee member) / Bryce, Alan (Committee member) / Arizona State University (Publisher)
Created2021
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Synthetic biology (SB) has become an important field of science focusing on designing and engineering new biological parts and systems, or re-designing existing biological systems for useful purposes. The dramatic growth of SB throughout the past two decades has not only provided us numerous achievements, but also brought us more

Synthetic biology (SB) has become an important field of science focusing on designing and engineering new biological parts and systems, or re-designing existing biological systems for useful purposes. The dramatic growth of SB throughout the past two decades has not only provided us numerous achievements, but also brought us more timely and underexplored problems. In SB's entire history, mathematical modeling has always been an indispensable approach to predict the experimental outcomes, improve experimental design and obtain mechanism-understanding of the biological systems. \textit{Escherichia coli} (\textit{E. coli}) is one of the most important experimental platforms, its growth dynamics is the major research objective in this dissertation. Chapter 2 employs a reaction-diffusion model to predict the \textit{E. coli} colony growth on a semi-solid agar plate under multiple controls. In that chapter, a density-dependent diffusion model with non-monotonic growth to capture the colony's non-linear growth profile is introduced. Findings of the new model to experimental data are compared and contrasted with those from other proposed models. In addition, the cross-sectional profile of the colony are computed and compared with experimental data. \textit{E. coli} colony is also used to perform spatial patterns driven by designed gene circuits. In Chapter 3, a gene circuit (MINPAC) and its corresponding pattern formation results are presented. Specifically, a series of partial differential equation (PDE) models are developed to describe the pattern formation driven by the MINPAC circuit. Model simulations of the patterns based on different experimental conditions and numerical analysis of the models to obtain a deeper understanding of the mechanisms are performed and discussed. Mathematical analysis of the simplified models, including traveling wave analysis and local stability analysis, is also presented and used to explore the control strategies of the pattern formation. The interaction between the gene circuit and the host \textit{E. coli} may be crucial and even greatly affect the experimental outcomes. Chapter 4 focuses on the growth feedback between the circuit and the host cell under different nutrient conditions. Two ordinary differential equation (ODE) models are developed to describe such feedback with nutrient variation. Preliminary results on data fitting using both two models and the model dynamical analysis are included.
ContributorsHe, Changhan (Author) / Kuang, Yang (Thesis advisor) / Wang, Xiao (Committee member) / Kostelich, Eric (Committee member) / Tian, Xiaojun (Committee member) / Gumel, Abba (Committee member) / Arizona State University (Publisher)
Created2021
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The purpose of this report is to review the current literature concerning management of the COVID-19 pandemic in homeless populations, and to use it to analyze the specific interventions established in Maricopa County—such as those aimed at education, vaccination and testing, and maintaining continuity of care. In doing so, I

The purpose of this report is to review the current literature concerning management of the COVID-19 pandemic in homeless populations, and to use it to analyze the specific interventions established in Maricopa County—such as those aimed at education, vaccination and testing, and maintaining continuity of care. In doing so, I hope to illustrate the unique challenges faced by people experiencing homelessness, provide context for disparities in health outcome, and inform action for both the ongoing pandemic and future outbreaks
ContributorsNewell, James (Author) / Gaughan, Monica (Thesis director) / Hruschka, Daniel (Committee member) / Barrett, The Honors College (Contributor) / School of Human Evolution & Social Change (Contributor) / School of Life Sciences (Contributor) / Watts College of Public Service & Community Solut (Contributor)
Created2022-05
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Opioid use disorder (OUD) has been a growing problem in the United States since the start of the 20th century, but a new wave of the “Opioid Epidemic” began in the mid-1990s when the use of opioid analgesics became the premier method for treating acute pain. In response to the

Opioid use disorder (OUD) has been a growing problem in the United States since the start of the 20th century, but a new wave of the “Opioid Epidemic” began in the mid-1990s when the use of opioid analgesics became the premier method for treating acute pain. In response to the increasing rates of OUD, in 2002 the Federal Drug Administration (FDA) approved a treatment course known as medication-assisted treatment (MAT), which is a combination therapy that uses buprenorphine, a partial opioid analgesic, and behavioral therapy to treat OUD. However, the use of buprenorphine to treat OUD is relatively controversial and as a result, is not widespread in primary care settings. New Mexico is an area that has seen some of the highest rates of OUD, with patient populations that suffer from the disorder prevalent in both rural and urban areas. This paper seeks to identify the barriers that urban and rural medical providers face when it comes to successfully establishing medication-assisted treatment options for opioid use disorder patients. To answer this question, 20 medical practitioners across the state of New Mexico shared their opinions on the subject in semi-structured interviews. A qualitative analysis of the information gathered from these interviews concluded that there are 3 main barriers (patient-related, provider-related, and medical system-related) that contribute to the inconsistent spread of MAT services in New Mexico. These barriers are relatively consistent across both rural and urban communities, however, in specific instances, they manifest differently. The preliminary findings from this study highlight multiple methods for reducing barriers to the implementation of MAT including starting provider education about OUD and MAT earlier (i.e. in residency) and improving the infrastructure and support systems available to vulnerable patient groups (including those in rural areas and homeless individuals).
ContributorsPentecost, Abigail (Author) / Hruschka, Daniel (Thesis director) / Drake, Alexandria (Committee member) / Barrett, The Honors College (Contributor) / School of Human Evolution & Social Change (Contributor) / School of Life Sciences (Contributor)
Created2022-05