Matching Items (130)
Description
Alzheimer’s disease (AD) is a neurodegenerative disease resulting in loss of cognitive function and is not considered part of the typical aging process. Recently, research is being conducted to study environmental effects on AD because the exact molecular mechanisms behind AD are not known. The associations between various toxins and AD have been mixed and unclear. In order to better understand the role of the environment and toxic substances on AD, we conducted a literature review and geospatial analysis of environmental, specifically wastewater, contaminants that have biological plausibility for increasing risk of development or exacerbation of AD. This literature review assisted us in selecting 10 wastewater toxic substances that displayed a mixed or one-sided relationship with the symptoms or prevalence of Alzheimer’s for our data analysis. We utilized data of toxic substances in wastewater treatment plants and compared them to the crude rate of AD in the different Census regions of the United States to test for possible linear relationships. Using data from the Targeted National Sewage Sludge Survey (TNSSS) and the Centers for Disease Control and Prevention (CDC), we developed an application using R Shiny to allow users to interactively visualize both datasets as choropleths of the United States and understand the importance of this area of research. Pearson’s correlation coefficient was calculated resulting in arsenic and cadmium displaying positive linear correlations with AD. Other analytes from this statistical analysis demonstrated mixed correlations with AD. This application and data analysis serve as a model in the methodology for further geospatial analysis on AD. Further data analysis and visualization at a lower level in terms of scope is necessary for more accurate and reliable evidence of a causal relationship between the wastewater substance analytes and AD.
GitHub Repository: https://github.com/komal-agrawal/AD_GIS.git
GitHub Repository: https://github.com/komal-agrawal/AD_GIS.git
ContributorsAgrawal, Komal (Author) / Scotch, Matthew (Thesis director) / Halden, Rolf (Committee member) / College of Health Solutions (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
An intimate view of the unique architecture of Harpegnathos saltwater nest using aluminum nest casts
Description
Abstract:
Given the incredible variety in ant nest architecture, this experiment sought to evaluate how the nest architecture of Harpegnathos saltator differs from other species’ nests. To achieve the ability to evaluate the structure of H. saltator nest, we created experimental colonies varying in size from 20, 40, 60, 80 workers of Harpegnathos saltator in five-gallon buckets of sand and then allowing the colonies to grow for four months and twelve days. To create the nest casts, we developed a charcoal kiln out of a galvanized trash can and used a ceramic crucible to hold the aluminum being melted. Using molten aluminum to create nest casts of each colony produced, we obtained three poorly developed nests and one decent nest. The decent nest cast, the 80 worker H. saltator nest, was lacking key features of H. saltator nests that have been excavated in the field. However, they do share many of the same structures such as the shaping of the chambers. The ability of the experimental colonies to excavate the soil provided in the buckets to them was likely halted by poor penetration of water into superficial layers of the soil, thus making the soil too difficult to excavate and form the structures that are key elements of the species nest architecture. Despite these key challenges which the colonies faced, the 80-worker colony showed extensive vertical development and did display features associated with natural H. saltator colonies. Thus, given the display of some key features associated with characteristics of the H. saltator nests excavated in the field, it can be said that with some modification to technique that this is a viable avenue for future study of nest architecture and colony structure.
Given the incredible variety in ant nest architecture, this experiment sought to evaluate how the nest architecture of Harpegnathos saltator differs from other species’ nests. To achieve the ability to evaluate the structure of H. saltator nest, we created experimental colonies varying in size from 20, 40, 60, 80 workers of Harpegnathos saltator in five-gallon buckets of sand and then allowing the colonies to grow for four months and twelve days. To create the nest casts, we developed a charcoal kiln out of a galvanized trash can and used a ceramic crucible to hold the aluminum being melted. Using molten aluminum to create nest casts of each colony produced, we obtained three poorly developed nests and one decent nest. The decent nest cast, the 80 worker H. saltator nest, was lacking key features of H. saltator nests that have been excavated in the field. However, they do share many of the same structures such as the shaping of the chambers. The ability of the experimental colonies to excavate the soil provided in the buckets to them was likely halted by poor penetration of water into superficial layers of the soil, thus making the soil too difficult to excavate and form the structures that are key elements of the species nest architecture. Despite these key challenges which the colonies faced, the 80-worker colony showed extensive vertical development and did display features associated with natural H. saltator colonies. Thus, given the display of some key features associated with characteristics of the H. saltator nests excavated in the field, it can be said that with some modification to technique that this is a viable avenue for future study of nest architecture and colony structure.
ContributorsAnderson, Clayton Edward (Author) / Liebig, Juergen (Thesis director) / Pratt, Stephen (Committee member) / School of Politics and Global Studies (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
With a rapidly decreasing amount of resources for construction, wood and bamboo have been suggested as renewable materials for increased use in the future to attain sustainability. Through a literature review, bamboo and wood growth, manufacturing and structural attributes were compared and then scored in a weighted matrix to determine the option that shows the higher rate of sustainability. In regards to the growth phase, which includes water usage, land usage, growth time, bamboo and wood showed similar characteristics overall, with wood scoring 1.11% higher than bamboo. Manufacturing, which captures the extraction and milling processes, is experiencing use of wood at levels four times those of bamboo, as bamboo production has not reached the efficiency of wood within the United States. Structural use proved to display bamboo’s power, as it scored 30% higher than wood. Overall, bamboo received a score 15% greater than that of wood, identifying this fast growing plant as the comparatively more sustainable construction material.
ContributorsThies, Jett Martin (Author) / Ward, Kristen (Thesis director) / Halden, Rolf (Committee member) / Industrial, Systems & Operations Engineering Prgm (Contributor) / Civil, Environmental and Sustainable Eng Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Complex animal societies consist of a plethora of interactions between members. To successfully thrive they must be able to recognize members and their kin, and to understand how they do this we need sufficient and reliable methods of testing. Eusocial insects are especially good at recognizing their nestmates, but the exact mechanism or how well they can discriminate is unknown. Ants achieve nestmate recognition by identifying varying proportions of cuticular hydrocarbons. Previous studies have shown ants can be trained to discriminate between pairs of hydrocarbons. This study aims to compare two methodologies previously shown to demonstrate odor learning to identify which one is the most promising to use for future odor learning experiments. The two methods tested were adapted from Sharma et al. (2015) and Guerrieri and d’Ettorre (2010). The results showed that the Guerrieri method demonstrated learning better and was more reliable and faster than the Sharma method. The Guerrieri method should be used in future experiments regarding odor learning discrimination
ContributorsDavis, Cole (Author) / Liebig, Juergen (Thesis director) / Stephen, Pratt (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
For colonies of ponerine ant species, sterility regulation after a founding queen's death is not totally achieved in the worker caste, and the possibility of sexual reproduction is opened to workers. The persisting survival of these colonies is dependent on capturing the optimal reproductive ratio; yet, an informational gap bounds the mechanisms detailing the selection of new reproductives and the suppression of ovarian development in rejected reproductives. We investigated the mechanisms of worker policing, one of the primary methods of ovarian suppression, through continuous video observation for a period of five days at the start of colony instability. Observations suggest policing in H. saltator is performed by a majority of a colony, including potential reproductives, and requires multiple events to fully discourage ovarian growth.
ContributorsChien, Jeffrey (Co-author) / Barat Ali, Fatima (Co-author) / Kang, Yun (Thesis director) / Liebig, Juergen (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / Mechanical and Aerospace Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
Due to the widely accepted trend of urbanization displacing wildlife from their natural habitats and niches, many wildlife conservation organizations have sprouted up, even in Phoenix. Liberty Wildlife Foundation is one that rehabilitates avian wildlife. Several studies have mentioned an opposing theory: that urbanization helps conserve those species that have turned urban environments into a niche of their own. Since these wildlife conservation centers are localized in cities themselves, this brings into question these organizations' definitions of the term "wildlife." This study examined injury and recovery statistics to determine just how many of the patients admitted were conventional wildlife versus urban-dwelling city birds, and whether this classification had any effect on their likeliness of recovery and release. The data showed that out of over 130 species, a few key urban species contributed to an overwhelmingly large majority of injured birds admitted to the center in 2017; urban and non-urban birds, however, had relatively equal average release frequencies, demonstrating then that their likelihood of recovery was predominantly dependent on the injury borne by them.
ContributorsVirdee, Rishika Kaur (Author) / Liebig, Juergen (Thesis director) / Lynch, John (Committee member) / Haight, Kevin (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
As the frequency of US-based disasters increases, so does the need for effective governmental contingency planning and improvement. The current, external evaluation method presents several opportunities for improvement, including cost, efficacy of results, and turnaround time for results. Utilizing a tabletop exercise as it's model, this study designed a self-evaluation tool to test if the data provided by such a tool is similar to the data provided by an external evaluator. After testing it in a government-sanctioned tabletop exercise, the tool showed its ability to be utilized in an exercise and evaluate the participants, based off their perceived success in the exercise. The results of the study indicate a strong, positive correlation between the results of the participant and evaluator populations surveyed as well as statistical equality between the two groups.
ContributorsEisen, Bryan Matthew (Author) / Hristovski, Kiril (Thesis director) / Ulrich, Jon (Committee member) / Gibbons, Sheri (Committee member) / Environmental and Resource Management (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Insects have intricate systems they depend on for survival. They live in societies where every individual plays an important role. Ants are a great example of this observation. They are known for having structurally sound societies that ensure the livelihood of the colony. The ant species analyzed for this research, Harpegnathos saltator, portrays a structured colony and serves as a useful example of levels of hierarchy. In the colony of H. saltator, one can find a queen, gamergates, workers, and male ants living underground in Southern India. Recording and analyzing egg-laying rates are important in this study because of the amount of information it provides. It is used especially when observing the relationship among the gamergates in colonies with varying colony sizes. Three different methods were used to record the egg-laying rates, each providing insight into valuable information. Results show that the smaller colonies with fewer identified gamergates do share an equal amount of egg-laying. In larger colonies, it appears that there are more active identified gamergates than others. Egg-laying duration times are smaller in colonies with fewer gamergates. It is also found that the presence of brood does not affect egg-laying rates and reproductive inhibition could be a possibility based on two of the colonies observed F65 and F21. Based on the data found, a more active colony that attempts to maintain stability by demonstrating aggression may be affecting the reproduction of gamergates. Future work that would further strengthen the research and conclusions made would involve further observation of colonies, both large and small, with varying numbers of gamergates. More observation involving behavior among gamergates and workers would also be beneficial. Mathematical modeling could also be incorporated to create equations that could determine information about colonies based on size, number of gamergates, and egg-laying rates.
ContributorsMayoral, Alejandra (Author) / Kang, Yun (Thesis director) / Liebig, Juergen (Committee member) / College of Integrative Sciences and Arts (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Conventional functional assays (FAs), which are used to describe the behaviors and assess the impacts of engineered nanomaterials (ENMs), have extensive human factor related errors (i.e. extraction process errors due to human laboratory skills), and consume considerable amounts of laboratory material. Consequently, there is a need and opportunity to improve conventional FAs by minimizing the potential for human factor related errors, reducing the usage of ENMs and reagents, and increase experimental reproducibility. The goal of this study was to simplify the conventional FAs and evaluate the feasibility and reproducibility of the simplified FAs. The underlying hypothesis implies that simplified FAs could quickly quantify the partitioning of nanoparticles between immiscible phases with minimum human factor related errors, low usage of ENMs, and high experimental reproducibility. Three different FAs were studied for this project: octanol-water assay, distribution to sediment assay, and cloud point extraction (CPE) assay. Three widely applied ENMs were selected: silver nanoparticles (AgNPs) coated with citrate, magnetite nanoparticles (Fe3O4) capped with polyvinyl pyrrolidone (PVP), and multiwall carbon nanotubes (MWCNTS) dispersed in an organic solution. Removal efficiency was the selected parameter used to describe the distribution of ENMs. Based on the variability and the t-tests on the removal efficiencies of conventional and simplified FAs, it is conclusive that the conventional octanol-water FAs on Fe3O4, the sediment FAs on Fe3O4, and the CPE FAs on MWCNTs and Fe3O4 can be simplified. The conventional octanol-water on AgNPs and the sediment FAs on AgNPs and MWCNTs cannot be simplified. It is inconclusive that the conventional octanol-water FAs on MWCNTs and the CPE FAs on AgNPs can be simplified, due to the uncertain causes and consistency of the differences on the removal efficiencies.
ContributorsChen, Zhihao (Author) / Hristovski, Kiril (Thesis director) / Kidd, Justin (Committee member) / Barrett, The Honors College (Contributor)
Created2017-05
Description
Insects are able to navigate their environments because they can detect hydrocarbons and volatile odors, but it is not clear which one has the fastest reaction when detected, or how much of a response can be produced due to either one. In order to determine which category of odorant is detected first as well as which one causes the highest response rate, data on electrophysiological responses from ants was analyzed. While the statistical tests can be done to understand and answer the questions raised by the study, there are various hydrocarbons and volatile odors that were not used in the data. Conclusive evidence only applies to the odorants used in the experiments.
ContributorsDarden, Jaelyn (Author) / Gerkin, Richard (Thesis director) / Liebig, Juergen (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05