Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
Displaying 1 - 8 of 8
Filtering by
- Creators: School of Life Sciences
Description
We examined the evolutionary morphological responses of Drosophila melanogaster that had evolved at constant cold (16°), constant hot (25°C), and fluctuating (16° and 25°C). Flies that were exposed to the constant low mean temperature developed larger thorax, wing, and cell sizes than those exposed to constant high mean temperatures. Males and females both responded similarly to thermal treatments in average wing and cell size. The resulting cell area for a given wing size in thermal fluctuating populations remains unclear and remains a subject for future research.
ContributorsAdrian, Gregory John (Author) / Angilletta, Michael (Thesis director) / Harrison, Jon (Committee member) / Rusch, Travis (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
In order to survive, species must regulate their intake of nutrients. In desert leafcutter ant colonies, acquisition of nutrients is not only important for maintaining the health of the colony, but also for the survival of a fungus which the ants cultivate and then consume. This multi-trophic, symbiotic relationship is relatively unique to leafcutter ants and interesting to researchers due to the complexity of how the individual foragers supply nutrients to both the colony and the fungus. The objective of this experiment is to study foraging rates and variation in macronutrient preference among foragers from the same colony of the desert leafcutter ant Acromyrmex versicolor. This study asks if individual foragers vary in their preference of protein to carbohydrate ratios when compared to the overall nutrient content of the colony, and how do these individuals respond as the nutrient content of the available diets increasingly deviates from the previously determined nutritional intake target ratio between 1 Protein:6.3 Carbohydrates to 1 Protein:7.5 Carbohydrates. It was hypothesized that foragers express individualized nutritional preferences that in aggregate balance colony macronutrient consumption, and the number of individuals collecting the diets would decrease as the available nutritional diets deviated away from the colony-level intake target of approximately 1P:7C. The results show trends that support the hypothesis that the number of foraging instances and the number of foragers who exhibit individualized preference towards a certain protein to carbohydrate ratio is highest when the colony is presented with diets that are closest to the colony nutritional intake target.
ContributorsGlovsky, Taylor Ella (Author) / Fewell, Jennifer (Thesis director) / Harrison, Jon (Committee member) / School of Life Sciences (Contributor) / Sanford School of Social and Family Dynamics (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Honeybees (Apis mellifera) are pollinators that face multiple challenges during foraging such as fungicides applied to floral sources. Fungicides are chemicals used to inhibit key fungal mechanisms like metabolism, but their effects remain relatively unknown in bees. In addition, studying the maturing bee can help us identify demographics that are more vulnerable to toxic materials like fungicides. The purpose of this study is test whether maturation and the fungicide Pristine influence the permeability of the blood-brain barrier. Specifically, we use a transportable dye to test how blood brain barrier transporter function responds to toxic insult and how it changes with age. Oral ingestion of Pristine by female workers did not have an effect on blood brain barrier permeability which suggests Pristine may have no or longer term consequences in the bee. However, blood brain barrier permeability changed with the bee's age which could be explained by the regulation of blood brain barrier transporters during natural transitions in hive task or the presence of hemolymph protein filtration
ContributorsPatel, Aamir S. (Author) / Amdam, Gro (Thesis director) / Harrison, Jon (Committee member) / Ozturk, Cahit (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Selenium, a group 16 metalloid on the periodic table, is a necessary mineral for many organisms. Trace amounts of selenium are essential for normal development, antioxidant protein function, enzyme function, and hormone regulation (Burden et al., 2016). However, when selenium is found in toxic amounts in organisms, it has been found to substitute for sulfur in proteins, which can be toxic to these animals, and cause oxidative stress (Quinn et al., 2007). Using the previous research done with acute exposure to organic and inorganic selenium compounds, we hypothesized that the inorganic sodium selenate would significantly decrease learning and memory recall for both chronic and acute exposure. We also hypothesized that the consumption of organic methylseleno-L-cysteine by honey bees would decrease learning and memory recall for both the chronic and acute exposure. We further hypothesized that protein carbonyl content would be increased due to oxidative damage caused by selenium in both the sodium selenate and the methylseleno-L-cysteine treatment groups, but that the inorganic selenium compound would increase the carbonyl content more than the methylseleno-L-cysteine. To run the experiments, three tents outside had two colonies in each tent. One tent contained the sodium selenate group, another had the sucrose control, and one contained the methylseleno-L-cysteine group. The treatment groups were fed selenium in their sucrose feeders. The first part of the experiment was training the bees by using proboscis extension response (PER) to teach them to extend their proboscis to the rewarded odor and not to the unrewarded odor. This was done by pairing the rewarded odor with a sucrose reward and not pairing it with the unrewarded odor. Then their short-term and long-term memory recall was tested. The second part of the experiment was checking for oxidative damage by measuring the protein carbonyl content in the bees. Three boxes were set up with the same three treatment groups as used in the tents. The treatment group bees were exposed to selenium in the sucrose feeders and in the pollen patties. After one week, the living bees were removed and frozen. They were then homogenized to extract protein. The first assay run was the protein content assay to establish a standard protein concentration for samples. Then a protein carbonyl assay was run, to determine the protein carbonyl content. Overall, the experiment found that exposure to selenium negatively impacted honey bees learning and memory recall significantly. Chronic exposure to the inorganic selenate reduced the bees' long-term memory abilities to differentiate between odors. With methylseleno-L-cysteine, it had no significant effect for the chronic exposure, but for the acute exposure, it had a significant impairment on their abilities to distinguish between the rewarded and unrewarded odors during conditioning. Our results showed that from our experiment there appeared to be no significant effect of selenium exposure on the increase of carbonylation content in the different treatment groups. This is most likely due to the fact the carbonyl content was not detectable because the protein concentration was low in the samples (approximately 3.5 mg/mL).
ContributorsWinski, Alexandra (Co-author) / Winski, Brandon (Co-author) / Smith, Brian (Thesis director) / Harrison, Jon (Committee member) / Burden, Christina (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Nutritional balance is a requirement for the survival of all species. This balance is important for complex eusocial organisms as it influences the growth and development of the colony. Leafcutter ants function as tri-trophic systems, harvesting mixed vegetation to cultivate a fungus garden that in return supplies the colony with food. Examining how the colony deals with nutrient balance is of particular interest because this species forages to provide nutrients for the fungus. There seems to be a feedback system between the fungus and the workers that influences how much of a particular macronutrient should be collected. The objective of this thesis study was to examine the foraging behavior of the desert leaf cutter ant, Acromyrmex versicolor. This study asked how nutrition, in particular the ratio of carbohydrates to proteins, influences the foraging behavior of the colony. It was hypothesized that given a choice of high protein and high carbohydrate diets the leafcutters would forage towards a balance ratio. The results from this experiment showed that A. versicolor forage towards a target ratio of protein to carbohydrate to based diets. This p:c ratio was calculated to be 1:6.2; 1 gram of protein to 6.2 grams of carbohydrate. When colonies were restricted to the high carbohydrate diet, they increased food consumption, consistent with the expectation that they would forage to reach their protein nutrient requirement, however, they reduced foraging on that diet. This suggests that ants avoid overconsuming protein, even when doing so provided more optimal carbohydrate intake. From this study I concluded that nutritional balance is a foraging goal for ant societies, similar to organisms. These results also open the question of how nutrient regulation by leafcutter ants is regulated around their mutualist relationship with another organism, the fungus.
ContributorsFarris, Megan Alexandra (Author) / Fewell, Jennifer (Thesis director) / Harrison, Jon (Committee member) / Smith, Nate (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2015-12
Description
Visual presentation of information is one method of learning that has the ability to enhance STEM learning compared to learning solely through text. Educational psychology research is ongoing in the STEM field for how students can learn better through visual representations in their course material. The goal of this study was to assess student responses to visual mini-lessons related to course content in the cardiovascular unit in Animal Physiology (BIO360) at Arizona State University. Study participants completed a series of eight mini-lessons and a survey on their experience with the visual lessons. The results of the survey identify increased desire for visual learning materials in STEM courses. The study participants reported that they felt more visual aids in their STEM courses would increase their understanding of course content and that their classroom performance would improve.
ContributorsRauch, Grace (Author) / Hartwell, Leland (Thesis director) / Harrison, Jon (Committee member) / Barrett, The Honors College (Contributor) / School of Human Evolution & Social Change (Contributor) / School of Life Sciences (Contributor)
Created2022-12
Description
Migration allows animals to track favorable environments and avoid harmful conditions but is energetically costly. There are different types of migration, such as tidal/daily, seasonal, and lifetime. Locust migratory swarms are one such famous phenomena that can have dramatic effects on human livelihoods. During long-distance flight, locusts rely on lipid oxidation from fat stores, while initial flight is fueled by carbohydrates. However, limited studies have tested how dietary macronutrients affect insect flight performance. Therefore, we asked: How do different dietary macronutrient ratios affect prolonged flight migration? We predicted that high carbohydrate diets would lead to high body lipid synthesis which would increase flight performance. We reared locusts in three crowded cages from 5th instar to adulthood on artificial diet varying in p:c ratio, supplemented with lettuce and water tubes, ad libitum. We used 7-14-day old adult males for flight performance assays where each day we used new individuals for tethered flight for 12 h in wind tunnels (~12 km·h-1) and video recorded their flight. We found that locust flight duration and quality increased with a decrease of dietary p:c ratio. Using control groups of locusts, we estimated that across 1 day of flight (up to 12 h), locusts lost on average in all treatments ~25 or ~30% of their total body lipid content. We concluded that long distance flight is improved by a high carbohydrate and low protein diet for L. migratoria by increasing their fuel sources. This work was supported by NSF # 1942054.
ContributorsParmar, Shivam (Author) / Cease, Arianne (Thesis director) / Talal, Stav (Committee member) / Harrison, Jon (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / School of Human Evolution & Social Change (Contributor)
Created2021-12
Adaptation of Camponotus floridanus’ Cuticular Hydrocarbon Profile under High Temperature Conditions
Description
Insects are small creatures highly susceptible to water loss. A major factor in the prevention of water loss through an insect’s cuticle are their cuticular hydrocarbons (CHC), a lipid layer consisting mostly of long-chain hydrocarbons. CHCs consist of different molecules called alkanes, alkenes, and methyl branched hydrocarbons which all have varying levels of hydrophobicity. Ants are a massively abundant family of insects with important roles in the ecosystem that also utilize CHCs. Camponotus floridanus isare athe native ant species of the Florida Keys which areis known to have variable environmental temperature. Being exposed to temperatures as high as 35 °C, these ants are expected to have mechanisms that allow them to adapt to their environment. It was hypothesized that CHCs may change in concentration or composition as a means to combat the changes in cuticular permeability due to the variable temperatures that the ants experience. We therefore used C. floridanus worker ants to learn more about CHC plasticity in insects when exposed to elevated temperatures. We found four CHC componentspeaks that showed a statistically significant increase in concentration when comparing the control to treatment colonies: 3,7 dimethyl C31, an underdetermined methyl branched C31, 3,7,11 trimethyl C31, and an undetermined tetramethylbranched C31. These significant changes in concentration occurred on longer chain hydrocarbons. Under further examination, it was found that there was a strong positive correlation between elution time and the differences in medians of peak area between control and treatment colonies. This shows that there was a shift in the CHC profile resulting in an increased concentration of longer chained methyl-branched hydrocarbons. It also suggests that branched hydrocarbons also play some role in the water proofing mechanism of C. floridanus.
ContributorsOn, Thomas (Co-author) / On, Tyler (Co-author) / Liebig, Juergen (Thesis director) / Harrison, Jon (Committee member) / Murdock, Tyler (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05