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Desert ecosystems are one of the fastest urbanizing areas on the planet. This rapid shift has the potential to alter the abundances and species richness of herbivore and plant communities. Herbivores, for example, are expected to be more abundant in urban desert remnant parks located within cities due to anthropogenic

Desert ecosystems are one of the fastest urbanizing areas on the planet. This rapid shift has the potential to alter the abundances and species richness of herbivore and plant communities. Herbivores, for example, are expected to be more abundant in urban desert remnant parks located within cities due to anthropogenic activities that concentrate food resources and reduce native predator populations. Despite this assumption, previous research conducted around Phoenix has shown that top-down herbivory led to equally reduced plant biomass. It is unclear if this insignificant difference in herbivory at rural and urban sites is due to unaltered desert herbivore populations or altered activity levels that counteract abundance differences. Vertebrate herbivore populations were surveyed at four sites inside and four sites outside of the core of Phoenix during fall 2014 and spring 2015 in order to determine whether abundances and richness differ significantly between urban and rural sites. In order to survey species composition and abundance at these sites, 100 Sherman traps and 8 larger wire traps that are designed to attract and capture small vertebrates such as mice, rats, and squirrels, were set at each site for two consecutive trap nights. Results suggest that the commonly assumed effect of urbanization on herbivore abundances does not apply to small rodent herbivore populations in a desert city, as overall small rodent abundances were statistically similar regardless of location. Though a significant difference was not found for species richness, a significant difference between small rodent genera richness at these sites was observed.
ContributorsAlvarez Guevara, Jessica Noemi (Co-author) / Ball, Becky A. (Co-author, Thesis director) / Hall, Sharon J. (Co-author) / Bateman, Heather (Committee member) / School of Sustainability (Contributor) / School of Mathematical and Natural Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
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Description
The retina is the lining in the back of the eye responsible for vision. When light photons hits the retina, the photoreceptors within the retina respond by sending impulses to the optic nerve, which connects to the brain. If there is injury to the eye or heredity retinal problems, this

The retina is the lining in the back of the eye responsible for vision. When light photons hits the retina, the photoreceptors within the retina respond by sending impulses to the optic nerve, which connects to the brain. If there is injury to the eye or heredity retinal problems, this part can become detached. Detachment leads to loss of nutrients, such as oxygen and glucose, to the cells in the eye and causes cell death. Sometimes the retina is able to be surgically reattached. If the photoreceptor cells have not died and the reattachment is successful, then these cells are able to regenerate their outer segments (OS) which are essential for their functionality and vitality. In this work we will explore how the regrowth of the photoreceptor cells in a healthy eye after retinal detachment can lead to a deeper understanding of how eye cells take up nutrients and regenerate. This work uses a mathematical model for a healthy eye in conjunction with data for photoreceptors' regrowth and decay. The parameters for the healthy eye model are estimated from the data and the ranges of these parameter values are centered +/- 10\% away from these values are used for sensitivity analysis. Using parameter estimation and sensitivity analysis we can better understand how certain processes represented by these parameters change within the model as a result of retinal detachment. Having a deeper understanding for any sort of photoreceptor death and growth can be used by the greater scientific community to help with these currently irreversible conditions that lead to blindness, such as retinal detachment. The analysis in this work shows that maximizing the carrying capacity of the trophic pool and the rate of RDCVF, as well as minimizing nutrient withdrawal of the rods and the cones from the trophic pool results in both the most regrowth and least cell death in retinal detachment.
ContributorsGoldman, Miriam Ayla (Author) / Camacho, Erikia (Thesis director) / Wirkus, Stephen (Committee member) / School of Mathematical and Natural Sciences (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description

This project aims to propose a novel approach for visualizing 4D geometry through the utilization of augmented reality (AR). While previous work has explored virtual reality (VR) as a means to bring 4D objects into a 3D environment, as well as 2D projections to display 4D geometry on screens, this

This project aims to propose a novel approach for visualizing 4D geometry through the utilization of augmented reality (AR). While previous work has explored virtual reality (VR) as a means to bring 4D objects into a 3D environment, as well as 2D projections to display 4D geometry on screens, this project seeks to extend the possibilities by leveraging the immersive nature of AR technology. By overlaying virtual 4D objects onto the real world, users can experience a more tangible representation and gain a deeper understanding of the complex structures present in higher dimensions.

ContributorsHum, Aaron (Author) / Nishimura, Joel (Thesis director) / Wang, Haiyan (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Natural Sciences (Contributor)
Created2023-05
ContributorsHum, Aaron (Author) / Nishimura, Joel (Thesis director) / Wang, Haiyan (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Natural Sciences (Contributor)
Created2023-05
Description
This project aims to propose a novel approach for visualizing 4D geometry through the utilization of augmented reality (AR). While previous work has explored virtual reality (VR) as a means to bring 4D objects into a 3D environment, as well as 2D projections to display 4D geometry on screens, this

This project aims to propose a novel approach for visualizing 4D geometry through the utilization of augmented reality (AR). While previous work has explored virtual reality (VR) as a means to bring 4D objects into a 3D environment, as well as 2D projections to display 4D geometry on screens, this project seeks to extend the possibilities by leveraging the immersive nature of AR technology. By overlaying virtual 4D objects onto the real world, users can experience a more tangible representation and gain a deeper understanding of the complex structures present in higher dimensions.
ContributorsHum, Aaron (Author) / Nishimura, Joel (Thesis director) / Wang, Haiyan (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Natural Sciences (Contributor)
Created2023-05
Description

Pollution causes many health problems in the modern world and the desert climates struggle with pollution in unique ways. In the Sonoran Desert, the research was conducted with the purpose of expanding the knowledge of the topic in this area. A literature review was conducted based on air, soil and

Pollution causes many health problems in the modern world and the desert climates struggle with pollution in unique ways. In the Sonoran Desert, the research was conducted with the purpose of expanding the knowledge of the topic in this area. A literature review was conducted based on air, soil and noise pollution in the region. The Sonoran Desert has high levels of carcinogenic elements along with other pollutants due to the main industries of mining, agriculture and manufacturing. Overall, these findings show people in desert climates deal with high levels of pollutants.

ContributorsWest, Katherine (Author) / Hackney Price, Jennifer (Thesis director) / Savalli, Udo (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Natural Sciences (Contributor)
Created2023-05
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Description

Aboveground-belowground relationships between vegetation and its associated soil biotic community play an important role in every terrestrial ecosystem for nutrient cycling and soil health maintenance. Deserts are especially sensitive to change and little is known about Sonoran Desert soil microbiota, while exotic herbaceous species are increasingly invading into the ecosystem

Aboveground-belowground relationships between vegetation and its associated soil biotic community play an important role in every terrestrial ecosystem for nutrient cycling and soil health maintenance. Deserts are especially sensitive to change and little is known about Sonoran Desert soil microbiota, while exotic herbaceous species are increasingly invading into the ecosystem with other harmful effects. In many other environments, soil communities have been associated with both plant species and plant functional type. The soil community food web depends on the sustenance brought by vegetation, and different soil community members are adapted to different diets. In this paper, we hypothesized that invasive plants would cause belowground soil communities to have greater abundance and lesser diversity than those under native, more locally established plants. To test this hypothesis, we selected four desert understory plant taxa: one native grass, one native forb, one invasive grass, and one invasive forb. We predicted that the invasive plants would be associated with a greater count of microarthropods per unit mass of soil but lesser microarthropod species diversity. The invasive plants were not statistically associated with a greater count of microarthropods per kilogram of soil nor lesser microarthropod species diversity. There was not a significant difference in abundance in the microarthropod categories between native and invasive plants, so the hypothesis was rejected. However, the invasive Erodium cicutarium was found to harbor high soil mite abundance, which warrants further study, and it is yet to be seen whether soil moisture and proximity to trees played a role in the data. The results of this study should help in generating more informed hypotheses regarding desert aboveground-belowground relationships.

ContributorsStern, Argon (Author) / Ball, Becky (Thesis director) / Sanin, Maria (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Natural Sciences (Contributor)
Created2022-05
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Description
The use of DNA testing has been focused primarily on biological samples such as blood or saliva found at crime scenes. These types of evidence in the forensic field are sometimes difficult to come by, especially when there is no body to find to verify things such as identity or

The use of DNA testing has been focused primarily on biological samples such as blood or saliva found at crime scenes. These types of evidence in the forensic field are sometimes difficult to come by, especially when there is no body to find to verify things such as identity or status of a person. In the case of the burial of a body, they can be remote and relocated multiple times depending on each situation. Clandestine burials are not uncommon especially in the Arizona desert by the United States and Mexico border. Since there is no physical body to find the next best avenue to finding a clandestine burial is through search teams which can take weeks to months or other expensive technology such as ground penetrating radar (GPR). A new more interesting avenue to search for bodies is using the most found material–soil. Technology has allowed the possibility of using soil DNA microbiome testing initially to study the varieties of microbes that compose in soil. Microbiomes are unique and plentiful and essentially inescapable as humans are hosts of millions of them. The idea of a microbiome footprint at a crime scene seems out of reach considering the millions of species that can be found in various areas. Yet it is not impossible to get a list of varieties of species that could indicate there was a body in the soil as microbiomes seep through from decomposition. This study determines the viability of using soil microbial DNA as a method of locating clandestine graves by testing 6 different locations of a previous pig decomposition simulation. These two locations give two different scenarios that a body may be found either exposed to the sun in an open field or hidden under foliage such as a tree in the Sonoran Desert. The experiment will also determine more factors that could contribute to a correlation of microbiome specific groups associated with decomposition in soil such as firmicutes. The use of soil microbial DNA testing could open the doors to more interpretation of information to eventually be on par with the forensic use of biological DNA testing which could potentially supplement testimonies on assumed burial locations that occurs frequently in criminal cases of body relocation and reburial.
ContributorsMata Salinas, Jennifer (Author) / Marshall, Pamela (Thesis director) / Bolhofner , Katelyn (Committee member) / Wang, Yue (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Natural Sciences (Contributor) / School of Humanities, Arts, and Cultural Studies (Contributor)
Created2022-05