ASU Electronic Theses and Dissertations
This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.
In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.
Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.
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- All Subjects: Biology
- Creators: Bateman, Heather L
- Creators: Crook, Sharon
Description
Modified and artificial water sources can be used as a management tool for game and non-game wildlife species. State, federal, and private agencies allocate significant resources to install and maintain artificial water sources (AWS) annually. Capture mark recapture methods were used to sample small mammal communities in the vicinity of five AWS and five paired control sites (treatments) in the surrounding Sonoran desert from October 2011 to May 2012. I measured plant species richness, density, and percent cover in the spring of 2012. A Multi-response Permutation Procedure was used to identify differences in small mammal community abundance, biomass, and species richness by season and treatment. I used Principle Component Analysis to reduce 11 habitat characteristics to five habitat factors. I related rodent occurrence to habitat characteristics using multiple and logistic regression. A total of 370 individual mammals representing three genera and eight species of rodents were captured across 4800 trap nights. Desert pocket mouse (Chaetodipus penicillatus) was the most common species in both seasons and treatments. Whereas rodent community abundance, biomass, and richness were similar between seasons, community variables of AWS were greater than CS. Rodent diversity was similar between treatments. Desert pocket mouse abundance and biomass were twice as high at AWS when compared to controls. Biomass of white-throated woodrat (Neotoma albigula) was five times greater at AWS. Habitat characteristics were similar between treatments. Neither presence of water nor distance to water explained substantial habitat variation. Occurrence of rodent species was associated with habitat characteristics. Desert rodent communities are adapted for arid environments (i.e. Heteromyids) and are not dependent on "free water". Higher abundances of desert pocket mouse at AWS were most likely related to increased disturbance and debris and not the presence of water. The results of this study and previous studies suggest that more investigation is needed and that short term studies may not be able to detect interactions (if any) between AWS and desert small mammal communities.
ContributorsSwitalski, Aaron (Author) / Bateman, Heather L (Thesis advisor) / Miller, William (Committee member) / Alford, Eddie (Committee member) / Arizona State University (Publisher)
Created2013
Description
Biological diversity is threatened by increasing anthropogenic modification of natural environments and increasing demands on natural resources. Sonoran desert tortoises (Gopherus morafkai) currently have Candidate status under the Endangered Species Act (ESA) based on health and habitat threats. To ensure this animal persists in the midst of multiple threats requires an understanding of the life history and ecology of each population. I looked at one physiological and one behavioral aspect of a population of tortoises at the Sugarloaf Mountain (SL) study site in central Arizona, USA. I used 21 years of capture-recapture records to estimate growth parameters of the entire population. I investigated habitat selection of juvenile tortoises by selecting 117 locations of 11 tortoises that had been tracked by radio-telemetry one to three times weekly for two years, selecting locations from both summer active season and during winter hibernation. I compared 22 microhabitat variables of tortoise locations to random SL locations to determine habitat use and availability. Male tortoises at SL reach a greater asymptotic length than females, and males and females appear to grow at the same rate. Juvenile tortoises at the SL site use steep rocky hillsides with high proportions of sand and annual vegetation, few succulents, and enclosed shelters in summer. They use enclosed shelters on steep slopes for winter hibernation. An understanding of these features can allow managers to quantify Sonoran desert tortoise habitat needs and life history characteristics and to understand the impact of land use policies.
ContributorsBridges, Andrew (Author) / Bateman, Heather L (Thesis advisor) / Miller, William (Committee member) / Ulrich, Jon (Committee member) / Arizona State University (Publisher)
Created2012
Description
The phycologist, M. R. Droop, studied vitamin B12 limitation in the flagellate Monochrysis lutheri and concluded that its specific growth rate depended on the concentration of the vitamin within the cell; i.e. the cell quota of the vitamin B12. The Droop model provides a mathematical expression to link growth rate to the intracellular concentration of a limiting nutrient. Although the Droop model has been an important modeling tool in ecology, it has only recently been applied to study cancer biology. Cancer cells live in an ecological setting, interacting and competing with normal and other cancerous cells for nutrients and space, and evolving and adapting to their environment. Here, the Droop equation is used to model three cancers.
First, prostate cancer is modeled, where androgen is considered the limiting nutrient since most tumors depend on androgen for proliferation and survival. The model's accuracy for predicting the biomarker for patients on intermittent androgen deprivation therapy is tested by comparing the simulation results to clinical data as well as to an existing simpler model. The results suggest that a simpler model may be more beneficial for a predictive use, although further research is needed in this field prior to implementing mathematical models as a predictive method in a clinical setting.
Next, two chronic myeloid leukemia models are compared that consider Imatinib treatment, a drug that inhibits the constitutively active tyrosine kinase BCR-ABL. Both models describe the competition of leukemic and normal cells, however the first model also describes intracellular dynamics by considering BCR-ABL as the limiting nutrient. Using clinical data, the differences in estimated parameters between the models and the capacity for each model to predict drug resistance are analyzed.
Last, a simple model is presented that considers ovarian tumor growth and tumor induced angiogenesis, subject to on and off anti-angiogenesis treatment. In this environment, the cell quota represents the intracellular concentration of necessary nutrients provided through blood supply. Mathematical analysis of the model is presented and model simulation results are compared to pre-clinical data. This simple model is able to fit both on- and off-treatment data using the same biologically relevant parameters.
First, prostate cancer is modeled, where androgen is considered the limiting nutrient since most tumors depend on androgen for proliferation and survival. The model's accuracy for predicting the biomarker for patients on intermittent androgen deprivation therapy is tested by comparing the simulation results to clinical data as well as to an existing simpler model. The results suggest that a simpler model may be more beneficial for a predictive use, although further research is needed in this field prior to implementing mathematical models as a predictive method in a clinical setting.
Next, two chronic myeloid leukemia models are compared that consider Imatinib treatment, a drug that inhibits the constitutively active tyrosine kinase BCR-ABL. Both models describe the competition of leukemic and normal cells, however the first model also describes intracellular dynamics by considering BCR-ABL as the limiting nutrient. Using clinical data, the differences in estimated parameters between the models and the capacity for each model to predict drug resistance are analyzed.
Last, a simple model is presented that considers ovarian tumor growth and tumor induced angiogenesis, subject to on and off anti-angiogenesis treatment. In this environment, the cell quota represents the intracellular concentration of necessary nutrients provided through blood supply. Mathematical analysis of the model is presented and model simulation results are compared to pre-clinical data. This simple model is able to fit both on- and off-treatment data using the same biologically relevant parameters.
ContributorsEverett, Rebecca Anne (Author) / Kuang, Yang (Thesis advisor) / Nagy, John (Committee member) / Milner, Fabio (Committee member) / Crook, Sharon (Committee member) / Jackiewicz, Zdzislaw (Committee member) / Arizona State University (Publisher)
Created2015
Description
Predicting resistant prostate cancer is critical for lowering medical costs and improving the quality of life of advanced prostate cancer patients. I formulate, compare, and analyze two mathematical models that aim to forecast future levels of prostate-specific antigen (PSA). I accomplish these tasks by employing clinical data of locally advanced prostate cancer patients undergoing androgen deprivation therapy (ADT). I demonstrate that the inverse problem of parameter estimation might be too complicated and simply relying on data fitting can give incorrect conclusions, since there is a large error in parameter values estimated and parameters might be unidentifiable. I provide confidence intervals to give estimate forecasts using data assimilation via an ensemble Kalman Filter. Using the ensemble Kalman Filter, I perform dual estimation of parameters and state variables to test the prediction accuracy of the models. Finally, I present a novel model with time delay and a delay-dependent parameter. I provide a geometric stability result to study the behavior of this model and show that the inclusion of time delay may improve the accuracy of predictions. Also, I demonstrate with clinical data that the inclusion of the delay-dependent parameter facilitates the identification and estimation of parameters.
ContributorsBaez, Javier (Author) / Kuang, Yang (Thesis advisor) / Kostelich, Eric (Committee member) / Crook, Sharon (Committee member) / Gardner, Carl (Committee member) / Nagy, John (Committee member) / Arizona State University (Publisher)
Created2017
Description
The built environment increases radiant heat exchange in urban areas by several degrees hotter compared to non-urban areas. Research has investigated how urbanization and heat affect human health; but there is scant literature on the effects of urban heat on wildlife. Animal body condition can be used to assess overall health. This parameter estimates the storage of energy-rich fat, which is important for growth, survival, and reproduction. The purpose of my research was to examine the Urban Heat Island effect on wild rodents across urban field sites spanning three strata of land surface temperature. Site level surface temperatures were measured using temperature data loggers and I captured 116 adult pocket mice (Chaetodipus spp. and Perognathus spp.) and Merriam’s kangaroo rats (Dipodomys merriami) to measure their body condition using accurate and noninvasive quantitative magnetic resonance. I used baited Sherman live traps from mid-May to early September during 2019 and 2020 in mountainous urban parks and open spaces over two summers. Rodents were captured at seven sites near the Phoenix metropolitan area; an ideal area for examining the effect of extreme heat experienced by urban wildlife. Results supported the prediction that rodent body condition was greatest in the cooler temperature stratas compared to the hottest temperature strata. I related rodent body condition to environmental predictors to dispute to environmental predictors to dispute alternative hypotheses; such as vegetation cover and degree of urbanization. Results based on measures of body fat and environmental predictors show pocket mice have more fat where vegetation is higher, nighttime temperatures are lower, surface temperatures are lower, and urbanization is greater. Kangaroo rats have more fat where surface temperature is lower. My results contribute to understanding the negative effects of extreme heat on body condition and generalized health experienced by urban wildlife because of the built environment. This research shows a need to investigate further impacts of urban heat on wildlife. Management suggestions for urban parks and open spaces include increasing vegetation cover, reducing impervious surface, and building with materials that reduce radiant heat.
ContributorsAllen, Brittany D'Ann (Author) / Bateman, Heather L (Thesis advisor) / Moore, Marianne S (Committee member) / Hondula, David M (Committee member) / Arizona State University (Publisher)
Created2021
Description
The Arizona toad (Anaxyrus microscaphus) is unique among bufonids because they primarily breed in streams of Arizona, New Mexico, Utah, and Nevada. Arizona toad is a species of conservation concern throughout their range. The non-native northern crayfish (Orconectes virilis) are opportunistic omnivores implicated in the declines of other native aquatic species. I wanted to determine occupancy, habitat use, and species interactions of the Arizona toad throughout its range Visual encounter surveys (VES) were completed by ASU and natural resource agency partners in the summers of 2021 and 2022 (n = 232) throughout Arizona toad range in Arizona. I used VES data and crayfish occurrence records, to determine interactions between the two species. I used broadscale environmental variables (1 km resolution) from WorldClim and EarthEnv to evaluate a relationship with Arizona toad occupancy across transects. These broadscale variables included bioclimatic variables, measures of habitat heterogeneity, measures of solar radiation, and topographic variables. In 2022 I collected fine-scale habitat data evaluating available vegetation cover and substrate composition within paired habitat plots. Fine-scale variables included canopy cover, substrate type, vegetation cover, and water depth. I applied multiple occupancy modeling approaches. Single-species model results found low toad occupancy, but high detection, as this is a rare species. Multi-species results showed no positive or negative relationship between Arizona toad and northern crayfish for both seasons. Two principal component analyses (PCA) were run on broadscale environmental variables and fine-scale habitat variables for 2021 and 2022, respectively, creating new synthetic variables for use in analysis. In 2021, the broadscale components were added to the single-species occupancy models and the top model included bioclimatic variables related to annual temperature range and precipitation. Arizona toad occupancy is lower with extreme hot temperatures and less precipitation. A logistic regression was run with the fine-scale habitat variables and the top model included PC1 and PC3. PC1 described elements related to riparian complexity, while PC3 described elements related to algae presence, including attached to cobble substrate. Arizona Toad select for certain habitats including canopy cover, shallow water, algae cover, and pebble cover. It is important to maintain riparian area habitat complexity and conserve habitat for the Arizona toad, a riparian stream specialist.
ContributorsMontgomery, Brett Joseph (Author) / Bateman, Heather L (Thesis advisor) / Albuquerque, Fabio S (Committee member) / Bogan, Michael T (Committee member) / Arizona State University (Publisher)
Created2023
Description
Human land use and land cover change alter key features of the landscape that may favor habitat selection by some species. Lizards are especially sensitive to these alterations because they rely on their external environment for regulating their body temperature. However, because of their diverse life-history traits and strategies, some are able to respond well to disturbance by using their habitat in various ways. To understand how they use their habitat and how human modifications may impact their ability to do this, biologists must identify where they occur and the habitat characteristics on which they depend. Therefore, I used species occupancy modeling to determine (1) whether disturbance predicts the presence of two sympatric congeneric (species of the same genus) lizard species Sceloporus grammicus and S. torquatus, and (2) which habitat characteristics are essential for predicting their occupancy and detection. I focused my study in central Mexico, a region of prevalent land use and land cover change. Here, I conducted visual encounter and habitat surveys at 100 1-hectare sites during the spring of 2019. I measured vegetation and ground cover, average tree diameter, and abundance of refuges. I recorded air temperature, relative humidity, and elevation. I summarized sites as either undisturbed or disturbed, based on the presence of human development. I also summarized sites by ecosystem type, desert or forest, based on vegetation composition (i.e., desert-adapted vs. non-desert-adapted plants), evidence of remnant forest, air temperature, and relative humidity. I found that S. torquatus was more likely to be present in disturbed habitat, whereas S. grammicus was more likely to be present in areas with leaf litter, tree cover, and woody debris. S. torquatus was twice as likely to be detected in forests than deserts, and S. grammicus was more likely to be detected at sites with high elevation and high relative humidity, low temperature, and herbaceous and grass cover. These results emphasize the utility of species occupancy modeling for estimating detection and occupancy in dynamic landscapes.
ContributorsFlores, Jennifer (Author) / Martins, Emília P. (Thesis advisor) / Bateman, Heather L (Thesis advisor) / Zuniga-Vega, J. Jaime (Committee member) / Arizona State University (Publisher)
Created2020
Description
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
Description
Riparian ecosystems comprise less than 2% of the landscape in the arid western U.S. yet provide habitat and resources to over half of arid-land wildlife species, including a broad diversity of anurans (frogs and toads). I surveyed anurans using passive acoustic monitoring to capture spring advertisement calls in wilderness area tributaries of the Verde River, Arizona, USA. In the spring and summer of 2021 and 2022, 13-29 autonomous recording units (ARUs) were deployed along perennial, intermittent, and ephemeral reaches across eight headwater streams. I characterized stream reaches based on the percent of pool, riffle, run, and side channel habitat within 100 meters of each ARU. I quantified substrate, discharge at 95% exceedance probability, flow width, and canopy cover at each site. To relate anuran occupancy and relative habitat use to environmental and hydrological variables, I evaluated acoustic data using single-species occupancy and Royle-Nichols and N-mixture (relative habitat use) models. Four species were detected in this study: canyon treefrog (Hyla arenicolor), red-spotted toad (Anaxyrus punctatus), Woodhouse’s toad (Anaxyrus woodhousii), and non-native American bullfrog (Lithobates catesbeianus), with canyon treefrog being the most ubiquitous species observed. Occupancy of canyon treefrog was greater at perennial and intermittent sites compared to ephemeral sites, and presence of pool was the most important driver of canyon treefrog occupancy and relative habitat use. Notably, this study did not detect several species with historical records in the middle Verde River watershed, including Arizona toad (Anaxyrus microscaphus) and Northern leopard frog (Lithobates pipiens). Given climate change-related flow declines and intensifying demands for water in the Southwest, maintaining stream flows that provide consistent and suitable hydroregimes for anuran breeding and larval development is of increasing importance. Determining habitat use and flow regimes necessary to support anuran populations can aid in prioritization of conservation actions related to water management and predict how changes in water availability may impact stream-breeding anurans.
ContributorsHuck, Margaret (Author) / Bateman, Heather L (Thesis advisor) / Albuquerque, Fabio S (Thesis advisor) / Lewis, Jesse S (Committee member) / Arizona State University (Publisher)
Created2023