Matching Items (445)
Description

Located directly south of Pima County, Arizona, there is a culturally rich community known as Santa Cruz County, Arizona. Santa Cruz County is a smaller community being home to an estimated 47,000 people. Santa Cruz County has a rich history given its proximity to the United States-Mexico border. One example

Located directly south of Pima County, Arizona, there is a culturally rich community known as Santa Cruz County, Arizona. Santa Cruz County is a smaller community being home to an estimated 47,000 people. Santa Cruz County has a rich history given its proximity to the United States-Mexico border. One example of this rich history can be found at the Tumacacori National Historical Park (NHP) with the attractive and unique ruins. The Tumacacori NHP was once an active Spanish mission that oversaw the religious expansion and communal resources. While the Tumacacori NHP no longer operates in this manner, it does serve an important role in providing visitors with a diverse and immersive look into the history of the region and the Tumacacori mission. While the Tumacacori NHP is meant to be a place for all people to visit, most visitors are not from the local community. The reason for this stems from a lack of educational and engagement opportunities between the Tumacacori NHP and the community youth, mainly due to community members being unaware of the park’s existence or the programs that are offered. This project analyzes and uncovers this disconnect as well as the barriers between the Tumacacori NHP and the Santa Cruz County youth through a research study and the use of children’s literature.

Created2021-12
Description

Influenza virus A (IVA) poses a serious threat to human health, killing over 25,000 Americans in the 2022 flu season alone. In the past 10 years, vaccine efficacy has varied significantly, ranging from 20-60% each season. Because IVA is subject to high antigenic shift and strain cocirculation, more effective IVA

Influenza virus A (IVA) poses a serious threat to human health, killing over 25,000 Americans in the 2022 flu season alone. In the past 10 years, vaccine efficacy has varied significantly, ranging from 20-60% each season. Because IVA is subject to high antigenic shift and strain cocirculation, more effective IVA vaccines are needed to reduce the incidence of disease. Herein we report the production of a recombinant immune complex (RIC) vaccine “4xM2e” in Nicotiana benthamiana plants using agroinfiltration for use as a potential universal IVA vaccine candidate. RICs fuse antigen to the C-terminus of an immunoglobulin heavy chain with an epitope tag cognate to the antibody, promoting immune complex formation to increase immunogenicity. IVA matrix protein 2 ectodomain (M2e) is selected to serve as vaccine antigen for its high sequence conservation, as only a small number of minor mutations have occurred since its discovery in 1981 in the human sequence. However, there is some divergence in zoonotic IVA strains, and to account for this, we designed a combination of human consensus, swine, and avian M2e variants, 4xM2e. This was fused to the C terminus of the RIC platform to improve M2e immunogenicity and IVA strain coverage. The 4xM2e RIC was produced in N. benthamiana and verified with SDS-PAGE and Western blot assays, along with an analysis of complex formation and the potential for complement activation via complement C1q ELISA. With this work, we demonstrate the potential of RICs and plant-expression systems to generate universal IVA vaccine candidates.

ContributorsLesio, Joshua (Author) / Mason, Hugh (Thesis director) / Holechek, Susan (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor) / School of Life Sciences (Contributor)
Created2023-05
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DescriptionThis thesis explores what factors have hindered the effectiveness of international aid in promoting sustainable development—an approach that focuses on not just immediate responses, but long-term changes that promote the well-being of current and future generations in relation to environmental degradation, social equity, and economic growth—in Haiti.
ContributorsLee, Rachel (Author) / Aggarwal, Rimjhim (Thesis director) / Mueller, Valerie (Committee member) / Sivak, Henry (Committee member) / Barrett, The Honors College (Contributor) / Watts College of Public Service & Community Solut (Contributor) / School of Sustainability (Contributor) / School of Politics and Global Studies (Contributor)
Created2022-05
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Description

Since 800 CE— long before the creation of the National Park Service (NPS) in 1905 — the Havasupai Tribe has depended on the natural resources and diverse ecosystem of the Grand Canyon. A deeper examination of how the national park came to fruition however demonstrates an often negated and harrowing

Since 800 CE— long before the creation of the National Park Service (NPS) in 1905 — the Havasupai Tribe has depended on the natural resources and diverse ecosystem of the Grand Canyon. A deeper examination of how the national park came to fruition however demonstrates an often negated and harrowing history of land theft, forced assimilation via reservation systems, and genocide. Political ecology is a way of considering how power dynamics, resource management, and society intersect. In the United States, this approach exposes the ways that anti-Indigenous legislation originating in the Department of the Interior has functioned both as a driver of ecosystem degradation and structural barricades to Native American self-determination. In order to achieve a just and sustainable future for all, it is necessary to dismantle hegemonic discourses regarding Indigenous communities.

ContributorsRuiz, Marissa (Author) / Jakubczak, Laura (Thesis director) / Ostling, Michael (Committee member) / Barrett, The Honors College (Contributor) / School of Politics and Global Studies (Contributor) / School of Sustainability (Contributor)
Created2022-05
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Description
In urban planning and design, creating emotional bonds, known as place identity, between people and their surroundings is paramount to improving the well-being of those who reside there. However, determining how to alter the built environment in order to increase place identity is a difficult task to achieve. Walkability is

In urban planning and design, creating emotional bonds, known as place identity, between people and their surroundings is paramount to improving the well-being of those who reside there. However, determining how to alter the built environment in order to increase place identity is a difficult task to achieve. Walkability is a good mechanistic link between the built environment and place identity. Walkability is comprised of a suite of factors that take into consideration both the natural and built environment. This thesis aims to determine if walkability is positively correlated with place identity in an extreme climate such as Phoenix. To test this, ecosystem services and disservices are used as factors to measure overall walkability. We found that access to recreational opportunities, aesthetic features of the pathway, and safety were all significant predictors of place identity. This has positive implications for walkable infrastructure to be strengthened in desert cities.
ContributorsSiefert, Janelle (Author) / Larson, Kelli (Thesis director) / Kelley, Jason (Committee member) / Barrett, The Honors College (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / School of Sustainability (Contributor) / Watts College of Public Service & Community Solut (Contributor)
Created2022-05
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Description
For many species, migration evolves to allow organisms to access better resources. However, the proximate factors that trigger these developmental changes, and how and why these vary across species, remain poorly understood. One prominent hypothesis is that poor-quality food promotes development of migratory phenotypes and this has been clearly shown

For many species, migration evolves to allow organisms to access better resources. However, the proximate factors that trigger these developmental changes, and how and why these vary across species, remain poorly understood. One prominent hypothesis is that poor-quality food promotes development of migratory phenotypes and this has been clearly shown for some polyphenic insects. In other animals, particularly long-distance bird migrants, it is clear that high-quality food is required to prepare animals for a successful migration. We tested the effect of diet quality on the flight behaviour and morphology of the Mongolian locust, Oedaleus asiaticus. Locusts reared at high population density and fed low-N grass (performance-enhancing for this species) had enhanced migratory morphology relative to locusts fed high-N grass. Furthermore, locusts fed synthetic diets with an optimal 1 : 2 protein : carbohydrate ratio flew for longer times than locusts fed diets with lower or higher protein : carbohydrate ratios. In contrast to the hypothesis that performance-degrading food should enhance migration, our results support the more nuanced hypothesis that high-quality diets promote development of migratory characteristics when migration is physiologically challenging.
ContributorsCease, Arianne (Author) / Harrison, Jon (Author) / Hao, Shuguang (Author) / Niren, Danielle (Author) / Zhang, Guangming (Author) / Kang, Le (Author) / Elser, James (Author) / Julie Ann Wrigley Global Institute of Sustainability (Contributor) / School of Sustainability (Contributor) / College of Liberal Arts and Sciences (Contributor) / School of Life Sciences (Contributor)
Created2017-06-07
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Description
Fire is one of the earliest and most common tools used by humans to modify the earth surface. Landscapes in the Yucatán Peninsula are composed of a mosaic of old growth subtropical forest, secondary vegetation, grasslands, and agricultural land that represent a well-documented example of anthropogenic intervention, much of which

Fire is one of the earliest and most common tools used by humans to modify the earth surface. Landscapes in the Yucatán Peninsula are composed of a mosaic of old growth subtropical forest, secondary vegetation, grasslands, and agricultural land that represent a well-documented example of anthropogenic intervention, much of which involves the use of fire. This research characterizes land use systems and land cover changes in the Yucatán during the 2000–2010 time period. We used an active fire remotely sensed data time series from the Moderate Resolution Imaging Spectroradiometer (MODIS), in combination with forest loss, and anthrome map sources to (1) establish the association between fire and land use change in the region; and (2) explore links between the spatial and temporal patterns of fire and specific types of land use practices, including within- and between-anthromes variability. A spatial multinomial logit model was constructed using fire, landscape configuration, and a set of commonly used control variables to estimate forest persistence, non-forest persistence, and change. Cross-tabulations and descriptive statistics were used to explore the relationships between fire occurrence, location, and timing with respect to the geography of land use. We also compared fire frequencies within and between anthrome groups using a negative binomial model and Tukey pairwise comparisons. Results show that fire data broadly reproduce the geography and timing of anthropogenic land change. Findings indicate that fire and landscape configuration is useful in explaining forest change and non-forest persistence, especially in fragmented (mosaicked) landscapes. Absence of fire occurrence is related usefully to the persistence of spatially continuous core areas of older growth forest. Fire has a positive relationship with forest to non-forest change and a negative relationship with forest persistence. Fire is also a good indicator to distinguish between anthrome groups (e.g., croplands and villages). Our study suggests that active fire data series are a reasonable proxy for anthropogenic land persistence/change in the context of the Yucatán and are useful to differentiate quantitatively and qualitatively between and within anthromes.
Created2017-09-12
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Description
Nitrogen (N) and phosphorus (P) are important limiting nutrients for plant production and consumer performance in a variety of ecosystems. As a result, the N:P stoichiometry of herbivores has received increased attention in ecology. However, the mechanisms by which herbivores maintain N:P stoichiometric homeostasis are poorly understood. Here, using a

Nitrogen (N) and phosphorus (P) are important limiting nutrients for plant production and consumer performance in a variety of ecosystems. As a result, the N:P stoichiometry of herbivores has received increased attention in ecology. However, the mechanisms by which herbivores maintain N:P stoichiometric homeostasis are poorly understood. Here, using a field manipulation experiment we show that the grasshopper Oedaleus asiaticus maintains strong N:P stoichiometric homeostasis regardless of whether grasshoppers were reared at low or high density. Grasshoppers maintained homeostasis by increasing P excretion when eating plants with higher P contents. However, while grasshoppers also maintained constant body N contents, we found no changes in N excretion in response to changing plant N content over the range measured. These results suggest that O. asiaticus maintains P homeostasis primarily by changing P absorption and excretion rates, but that other mechanisms may be more important for regulating N homeostasis. Our findings improve our understanding of consumer-driven P recycling and may help in understanding the factors affecting plant-herbivore interactions and ecosystem processes in grasslands.
ContributorsZhang, Zijia (Author) / Elser, James (Author) / Cease, Arianne (Author) / Zhang, Ximei (Author) / Yu, Qiang (Author) / Han, Xingguo (Author) / Zhang, Guangming (Author) / College of Liberal Arts and Sciences (Contributor) / School of Life Sciences (Contributor) / Julie Ann Wrigley Global Institute of Sustainability (Contributor) / School of Sustainability (Contributor)
Created2014-08-04
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Description
The growth rate hypothesis (GRH) proposes that higher growth rate (the rate of change in biomass per unit biomass, μ) is associated with higher P concentration and lower C∶P and N∶P ratios. However, the applicability of the GRH to vascular plants is not well-studied and few studies have been done

The growth rate hypothesis (GRH) proposes that higher growth rate (the rate of change in biomass per unit biomass, μ) is associated with higher P concentration and lower C∶P and N∶P ratios. However, the applicability of the GRH to vascular plants is not well-studied and few studies have been done on belowground biomass. Here we showed that, for aboveground, belowground and total biomass of three study species, μ was positively correlated with N∶C under N limitation and positively correlated with P∶C under P limitation. However, the N∶P ratio was a unimodal function of μ, increasing for small values of μ, reaching a maximum, and then decreasing. The range of variations in μ was positively correlated with variation in C∶N∶P stoichiometry. Furthermore, μ and C∶N∶P ranges for aboveground biomass were negatively correlated with those for belowground. Our results confirm the well-known association of growth rate with tissue concentration of the limiting nutrient and provide empirical support for recent theoretical formulations.
ContributorsYu, Qiang (Author) / Wu, Honghui (Author) / He, Nianpeng (Author) / Lu, Xiaotao (Author) / Wang, Zhiping (Author) / Elser, James (Author) / Wu, Jianguo (Author) / Han, Xingguo (Author) / College of Liberal Arts and Sciences (Contributor) / School of Life Sciences (Contributor) / Julie Ann Wrigley Global Institute of Sustainability (Contributor) / School of Sustainability (Contributor)
Created2012-03-13
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Description
Evolving Earth observation and change detection techniques enable the automatic identification of Land Use and Land Cover Change (LULCC) over a large extent from massive amounts of remote sensing data. It at the same time poses a major challenge in effective organization, representation and modeling of such information. This study

Evolving Earth observation and change detection techniques enable the automatic identification of Land Use and Land Cover Change (LULCC) over a large extent from massive amounts of remote sensing data. It at the same time poses a major challenge in effective organization, representation and modeling of such information. This study proposes and implements an integrated computational framework to support the modeling, semantic and spatial reasoning of change information with regard to space, time and topology. We first proposed a conceptual model to formally represent the spatiotemporal variation of change data, which is essential knowledge to support various environmental and social studies, such as deforestation and urbanization studies. Then, a spatial ontology was created to encode these semantic spatiotemporal data in a machine-understandable format. Based on the knowledge defined in the ontology and related reasoning rules, a semantic platform was developed to support the semantic query and change trajectory reasoning of areas with LULCC. This semantic platform is innovative, as it integrates semantic and spatial reasoning into a coherent computational and operational software framework to support automated semantic analysis of time series data that can go beyond LULC datasets. In addition, this system scales well as the amount of data increases, validated by a number of experimental results. This work contributes significantly to both the geospatial Semantic Web and GIScience communities in terms of the establishment of the (web-based) semantic platform for collaborative question answering and decision-making.
Created2016-10-25