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Characterizing Navajo Nation water sources for potential use with nanofiltration
No full textThis study is motivated by the need to increase access to clean and safe water on the Navajo Nation. Up to 30% of the Navajo Nation lacks access to public water systems; however, the expansion of water infrastructure across the Navajo Nation is not feasible considering its low population density. The natural abundance of uranium and arsenic in the southwest US, the potential for increased mobilization from previous mining activity, and the use of unregulated water for potable purposes can contribute to increased human exposure to uranium and arsenic on the Navajo Nation.A relatively new, decentralized, and affordable technology used in this study is solar nanofiltration (SNF). The SNF systems utilize nanofiltration, a water purification technique that can remove more than 90% of uranium (U) and arsenic (As) from water. Contaminant rejection is, however, variable, and dependent on the speciation of uranium and arsenic and on membrane fouling. Both speciation and membrane fouling are sensitive to pH, cations, and anions present. Additionally, membrane fouling can be affected by total organic carbon and bacteria concentrations.
A primary objective of this study was to use analytical techniques (including inductively coupled plasma mass spectrometry) to characterize the Dilkon Chapter House water source that will be filtered by the SNF system located in Dilkon, AZ. The uranium, arsenic, cation, and anion concentrations were below enforceable limits, and no bacterial growth was observed after 48 hours. All measured variables are not considered problematic for the SNF system at this time. To continue monitoring and maintaining the SNF, further analysis is needed.
A secondary objective was to survey the water sources in areas surrounding the Dilkon SNF, including water sources in Dilkon and Black Falls. From the seven sources sampled, two exceeded the U MCL and three exceeded the As MCL. Additionally, samples from the Dilkon area had higher TDS concentrations ranging from 300-16,000 mg/L. The final objective was to evaluate the efficiency of the ultraviolet (UV) disinfection attachments in Lupton. The Lupton heterotrophic plate count results showed no bacterial growth after 24 hours, demonstrating that the UV disinfection was effective
Mechanobiology of the aortic valve: a multiscale approach
No full textAortic stenosis (AS) is the most appeared disease in aortic valve diseases. Calcific aortic valve disease (CAVD) is the fundamental reason for AS. Herein, we present a computational model to represent the mechanobiology of the aortic valve caused by CAVD. This thesis aimed to study: 1- The effect of blood flow on the mass transport of biochemicals involved in CAVD near the aortic valve 2- Growth and remodeling of the aortic valve due to CAVD and aging to find a better understanding of AS 3- Coupling the mechanosensitive systems biology and cell signaling pathways with growth and remodeling in the tissue scale to have a comprehensive model of growth and remodeling due to CAVD and aging. First, the fluid-structure interaction (FSI) model coupled with mass transport of biochemicals near the aortic valve simulations were performed. A correlation between vortex structure and the concentration of biochemicals near the aortic valve was found. The results show that the vortex structure topology near the aortic valve can trap biochemicals causing CAVD. For the second aim, kinematic growth and remodeling of the aortic valve due to aging and calcification were modeled to see the effects in AS. Herein, growth and remodeling of the aortic valve due to aging and calcification were coupled with elastodynamics of the aortic valve. Our results show that the growth and remodeling of the aortic valve due to calcification have a crucial effect on the dynamic of the valve. The essential reduction in geometric orifice area due to CAVD and aging was observed. Also, the aortic valve dynamics dramatically changed after growth and remodeling due to CAVD and aging. Finally, cell signaling pathways that cause CAVD on the scale of minutes and hours were coupled with the growth and remodeling of the aortic valve at the tissue scale level, which takes years. A novel computational framework was developed to see the relation between these two temporal and spatial scales. Three test subjects (cube, idealized aneurysm, and an aortic valve) were developed, and different conditions were imposed. The system of ordinary differential equations (ODEs) and partial differential equations (PDEs) were modeled for systems biology at the cell-scale. Kinematic growth and remodeling were imposed as the tissue-scale. The results show that the concentration of biochemicals and reactions between them and the choice between the ODE and PDE modeling affect the growth patterns. Our results indicate that choosing a suitable model for systems biology can lead to a more satisfactory insight of growth in tissue scale
Disease dynamics, ecology, and biology of Coccidioides spp. in Arizona
No full textThe disease Valley fever (coccidioidomycosis, San Joaquin Valley Fever) is caused by two species of soil dwelling fungal pathogens within the genus Coccidioides (C. posadasii and C. immitis). Infection is established when a susceptible mammal inhales environmental arthroconidia shed from the saprobic lifecycle of the fungus. Although the lone route of infection comes from the environment, abiotic and biotic factors that influence the distribution and dispersal of the organism in the environment are poorly understood. My dissertation research is focused on using microbiological, molecular, and epidemiological tools to investigate the disease dynamics, basic biology, and ecology of these important fungal pathogens. In Chapter 1, I provide background information, a review of the literature, and highlight gaps in knowledge that are important to fully understanding these fungi. In Chapter 2 I employ sophisticated statistical models on epidemiological data from Arizona to gain insights into the seasonality of Valley fever. This study looked at specifically how climatic variables can predict outbreaks. This type of analysis can be used to improve public health surveillance of the disease and understand basic biology of the fungi in natural soil habitat. In brief, I found that temperature and water availability are crucial for the soil microbes of the hot and arid Sonoran Desert ecosystem. In Chapter 3, I experimentally examine how these factors influence the growth of the fungus and the discharge of infectious arthroconidia in soil and employ mechanistic growth models in order to predict the growth and shed pattern. Importantly, this is the first study to quantify this biological process and will aid the development of future disease models. Soil is an extremely complex habitat, with many biological interactions that can influence the distribution of populations of certain microbes. In Chapter 4 I examine the relationships of commonly occurring soil bacteria and fungi with Coccidioides spp. I use molecular tools to identify bacteria and fungi that are interacting with Coccidioides spp. at multiple sites in soil and examine whether these microbes have an antagonistic, synergistic, or neutral relationship with the pathogen. I then apply analytical chemistry techniques to characterize the secreted metabolites of the microbes with antagonistic properties. The goal of Chapter 4 is to identify microbes and/or metabolites that suppress the growth of Coccidioides spp. in hyper-endemic areas of Valley fever. Microbes with synergistic properties can also be used as indicator species for the presence of Coccidioides spp. in the soil. The knowledge gained from my dissertation helps to understand this deadly pathogen in the laboratory and in the field and improve disease modeling to prevent fatal infections of humans and domestic animals
Symbiotic communities and interactions in two major bark beetle systems relative to climate and tree chemical defenses
No full textBark beetle-killed trees are reservoirs of biodiversity in forest ecosystems. Bark beetles are associated with a variety of symbionts with whom they share complex ecological interactions. Symbiota of bark beetles directly and indirectly affect beetle population dynamics, which in turn determines [tree] host colonization, tree condition, and even landscape-level tree mortality patterns. Thus, bark beetle activities collectively shape forest ecosystems. These complex symbiotic interactions in bark beetle systems involve multiple biological groups, including fungi, bacteria, mites, nematodes, and the tree itself (their living biotic environment). These interactions are also climate dependent and can vary across large geographic scales. This variability in symbiotic community association is important for understanding beetle-disturbance patterns, identifying important co-evolutionary relationships, and for modeling climate-driven biotic shifts in various bark beetle systems that are locally adapted to their native environments. In this dissertation, I use large-scale geographic surveys to compare and contrast symbiotic community assemblages for an economically important bark beetle species (Dendroctonus ponderosae); and use a hypothesis-driven field experimental study to show that these community assemblages are locally adapted and respond variably to warming climates. Considering the susceptibility of conifers to bark beetles to climate-change driven drought, I also use field studies of pinyon bark beetle (Ips confusus) in a drought stressed pinyon pine environment to provide important information regarding tree chemical profiles in relation to bark beetles and climate. I use lab experimental studies to show that biotic tree responses (such as resin production and chemical profile) in drought stressed trees can influence the growth of fungi that are symbionts with pinyon bark beetles. I conclude this dissertation by summarizing the major ecological/ecosystem contributions of bark beetle symbionts and discuss the potential for direct management and the implications for existing management practices
Dense, longitudinal sampling reveals key gut microbial communities associated with Alzheimer’s disease pathologies
Get PDFThe gut microbiota, the aggregate of microbial cells that inhabit the gastrointestinal tract, communicates bidirectionally with the brain via immune, neural, metabolic, and endocrine pathways, known as the gut-brain axis. The gut-brain axis is suspected to contribute to the development of Alzheimer’s disease (AD). We hypothesize that specific gut microbiota compositions contribute to the development of AD pathologies and neuroinflammation via the gut-brain axis. To characterize the gut microbiota of 3xTg-AD mice modeling plaque deposition and hyperphosphorylated tau, fecal samples were collected fortnightly from 4 to 52 weeks of age, the V4 region of the 16S rRNA gene was amplified and sequenced on the Illumina MiSeq. Data were analyzed using QIIME 2. We have identified changes in the gut microbiota and immune response that may be predictive of the development of AD pathologies. To explore the effect of modulation of the gut microbiota in mice modeling AD pathologies, we performed fecal microbiota transplants (FMT) from aged (52-64 weeks) 3xTg-AD mice, which are modeling plaques and neurofibrillary tangles, to young 3xTg-AD (n=5) or wild-type mice (n=10) with the sequencing methods described above. We observed a shift in microbiota composition of FMT-treated mice when compared to control (PBS-treated) mice with no effect on neuroinflammation. To investigate the gut microbiota composition with high resolution taxonomic assignments and include fungi, viruses, and other eukaryotic microbes, shallow shotgun metagenomic sequencing (SSMS) was run on select samples from the initial longitudinal and subsequent FMT study. Bacteroides, Lactobacillus, and Turicibacter, identified in the studies using 16S rRNA gene sequencing, were classified at species and strain level using SSMS. Finally, a meta-analysis of the gut microbiota composition in WT mice bred at NAU compared to WT mice bred at Jackson Laboratories using our available 16S rRNA gene sequencing data was performed. Beta diversity metrics reveal mice bred at Jackson Laboratories had an adjustment period of about 6 months, before more closely resembling mice bred at NAU. Taken together, our work shows that 3xTg-AD mice harbor a unique gut microbiota composition, associated with disease pathologies, early in life, that becomes more similar to WT mice by 52 weeks of age. The microbial communities associated with later stages of modeling AD pathologies are more transferrable to other 3xTg-AD mice than WT mice, but do not alter neuroinflammation. Finally, SSMS revealed the species and strain level classification of the microbial communities of interest from the 16S rRNA gene sequencing data. Future studies investigating the role of Bacteroides fragilis, Turicibacter H121, Lactobacillus murinis, and Lactobacillus animalis in the gut microbiome of 3xTg-AD mice are warranted to uncover potential therapeutic targets in the gut microbiota-brain axis for AD
Perceptions of administrators, teachers, and parents on effective homework practices
No full textHomework is a well-established tradition ingrained in today’s educational system. Although it is a widely used practice in many elementary school classrooms, the research suggests that homework does not increase student achievement. For many students and their families, homework is a significant struggle. This research study aims to examine the perceptions of teachers, administrators, and parents of effective homework practices for students in elementary school. Since homework is a commonly used practice, educators must be given the opportunity and the resources to reflect on their practices and participate in a larger conversation regarding homework.
Research participants included teachers, administrators, and parents from three diverse elementary schools in a large suburban school district. Surveys were distributed to teachers, parents, and administrators. Focus group participants were selected based on the interest identified from the survey. Quantitative data were analyzed using descriptive statistics. Qualitative data was coded, and themes were identified.
The findings of this study suggest that teachers assign homework because they believe it increases student achievement for students in elementary school. Teachers give homework so that students can practice at home what is learned at school.
Teachers also believe that homework creates positive study habits and allows students to learn responsibility, organization, and time management. Administrators do not feel that the homework being assigned is increasing student achievement. They think that many parents are overly involved in project-based assignments. Administrators would support a no homework policy at their schools. Parents agree with teachers that homework increases student achievement. Overall, the topic of homework is not discussed with teachers. Teachers are not provided training on how to assign homework to their students. It is not a topic discussed during professional development, teacher training, or teacher preparation programs. Even though homework is a regularly occurring practice, it is never discussed with teachers. Teachers create homework policies in their classrooms based on their own beliefs or with guidance from mentor teachers. There is an excellent opportunity for growth in this well-established educational practice.
Although it is a routine practice for many children, homework can be a significant struggle for many students and their families. Students that struggle during the school day are forced to continue that struggle at home doing homework. Homework can ruin precious family time. Regardless of whether homework is a struggle, all children are forced to divide their time between leisure activities, extra-curricular activities, and required assignments after school. By evaluating their homework practices and policies, educators have an opportunity to make a significant difference in the educational lives of children
Canyon Boys
Get PDFMy first creative writing sample came in the form of a short story, written when I was in the third grade. The story itself followed a young child, lost amongst an animal farm, on the search for his missing teddy bear. What I remember next, was a poem, a haiku written in sixth grade about a bat. For years, I’ve thought about stories I’ve always wanted to tell, coming of age stories, horror stories, stories about my family, all inspired by storytelling within my family. It wasn’t until college under the guidance of Diné poet Orlando White, that I would first learn about Diné poetics, and literature. White introduced myself and other Diné students to his own poetry and writers like Sherwin Bitsui, Laura Tohe, and more. I’ve always held an interest in creating my own stories, but it was this experience that grew my admiration of poetics, and poetry’s ability to teach about love, history, and healing. During my time here at Northern Arizona University, I’ve chosen multiple classes that allowed me to study Indigenous literature. This genre often focuses on eco poetics and location-based storytelling, often dealing with historical events and the ways that generations of people survive. My experience with writing has always been informed by Indigenous authors and so my own writing is often based in landscape focusing on setting to tell a story.
Canyon Boys is a collection of poetry influenced by my hometown of Chinle, particularly my time growing up in and around Canyon De Chelly. As a Diné, I am always connected to the Canyon and this connection is felt within stories shared and experienced by my family as well and our stories as a family and as Diné people are shared throughout this collection. As a Diné male, I look toward my own male relatives for advice in growing. These past few years at NAU have turned me to think about my brother, my father, my grandparents and how their lives have influenced mine. This collection features several poems dedicated to these individuals to inform myself and readers of our identity as Diné men. The landscape that these characters interact in are often sandstone cliffs, cornfields, within huge red and brown canyon walls all influenced by the canyon’s influence as a place of survival, war, removal, returning, and healing. With this work I want to illustrate the experience of a Diné individual and what lessons can be learned when one reflects on their relationships with family, loved ones, and the landscape they choose for themselves.
Canyon De Chelly is significant to Diné people as it served as their homeland for thousands of years. It has also more recently served as a place of refuge for Diné hiding out during the forced relocation of southwestern tribes seen at the hands of the U.S. Government. There are stories of trauma as well as healing that people remember the Canyon for. Diné Poet Laureate, Laura Tohe has written about this extensively in her poetry. Her poetics inform us how landscape is essential to Diné identity and can be used a reference point for others as a way to navigate their own identity. I write poems to showcase stories and moments I experience as a Diné male and how each instance, no matter how small or brief, can offer healing and understanding of my cultural identity. Women are vital in any culture, especially Diné culture and their presence is felt heavily in community efforts of storytelling and healing. These past few years I have felt a lack of this guidance in the Diné community and in my own familial structures when thinking of the male individuals. I want to attribute my own understanding of healing and communicate my own struggles through my poetry, as a way to begin conversations for healing within my family. In writing poems dedicated to individuals and the landscapes which influence me, I explore that level of kinship, of connecting to my community through storytelling.
Though inspired by the narrative storytelling of Laura Tohe and Luci Tapahonso, I feel my strengths often come in imagery heavily influenced by writers like Sherwin Bitsui and Orlando White. These writers have served as my poetry teachers over my years of Undergrad and Graduate studies and their image-based poetics have given me insight as to how poetry can illustrate landscape, and how that landscape, given the time to tell the story, can offer guidance to historical events, generational healing, and powerful instruction into Diné identity. I want my poetry to be seen as a guide to healing, how our relationships to others especially landscape can influence our identity. These short moments of memories, of raw landscape and tradition, have helped me immensely to grow as an individual, and showcasing them through poetics provides me a way to connect back to my community. With love and honesty, this collection and others in the future will be dedicated to my fellow canyon boys
AMERICAN ROT
Get PDFAMERICAN ROT is a novel examining a near future in which the United States of America has dissolved into disparate nations. These new countries struggle to survive without their former networks while extremist beliefs thrive in this new ecosystem. From the perspective of Kansas and surrounding states, these places also deal with the fallout of soil overuse and toxic chemicals that have leaked into the dirt and aquifer. The story largely follows a mycologist who discovers a fungus that has the capability to restore the soil and remove the toxins from the aquifer, but with devastating side effects. The mycologist embarks on a journey to investigate the fungus in the hopes of saving an already diminished society from what could be the final blow, all while outrunning the new militants that have taken hold of the land. This novel examines the familiar political rifts in American society, the ways the degradation of soil mirrors the degradation of the American spirit, and how the magical kingdom of fungus uses death to create new life. This novel is structured in the classic framework of a Road Story, a genre that depicts a character passing through new places—places largely unknown to them—as they come to understand cultures and identities they had previously ignored. As such, this is story is meant to be a political awakening for the main character, as he moves from anhedonia-inspired apathy to an awareness of and engagement with the world around him.
American Rot was written over the course of the MFA and was inspired by lessons in Foucault’s concept of Biopolitics, the effects of capitalism and settler colonialism on the environment, and the magic of fungi
New approaches to agricultural commitment: a decolonized approach to agricultural commitments on Ndee lands
No full textArchaeologically, agricultural commitment defines the threshold state of a society that is organized around and reliant upon agriculture to meet most or all a group’s subsistence needs. There is a long history of invasive and extensive archaeological investigations at Grasshopper and Kinishba, two agriculturally committed Pueblo III (A.D. 1250- 1400) sites, that represent destructive and problematic histories of archaeological practice on Ndee lands. In collaboration with the White Mountain Apache Tribal Historic Preservation Office (WMA THPO) this thesis research takes a decolonized approach to engage with the past and present agricultural commitments on Ndee lands through interviews with community members. This thesis is guided by the Best Stewardship Practices set forth by WMA THPO and respectfully uses least impact methods of research such as interviews and soil analysis to discuss past and present agricultural commitment on Ndee lands. The outcome of this research intends to contribute to current Ndee food sovereignty initiatives and agricultural practices by Ndee people on Ndee lands
The re-emerging mission of the community college: community stakeholder narratives
No full textJohn Dewey (1916) asserted that deliberate and systematic educational systems provide capacity to all members of society in order to solve problems and is the foundation for participatory democratic education (Harbour, 2015). Learning is also a social process that allows people to live purposefully. The goal of this qualitative, narrative inquiry study was to explore the voices of rural community stakeholders and determine how their experiences have impacted their values of community and higher education. The primary research question in this study focused on how community stakeholders understand and value participatory democratic education in a rural community. This study explored 12 community stakeholder narratives value community and education. Participants were asked to share stories about their lives with a focus on their perceived value of education, community connectedness, and experiences with higher education institutions. Education as Growth, Education as Direction and Education as Social Function are three themes discovered in the stakeholder narratives and link Dewey’s philosophy of education from the early 1900’s to the current day. Findings suggest that participatory democratic education is valued by community stakeholders and should be a focus in community college education