Natural World

Recorded five-minute presentations for the Undergraduate Scholarly Showcase in Category C: Natural World, Projects C-01 through C-09.


C-01: Herbaria: Valuable, But Fragile Treasure Troves of Data

Michael Grandi, Biological Sciences
Project Advisor: Dr. Eric Tepe
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Awarded Excellence in Research Communication

The world's 3500 herbaria contain nearly 300 million specimens with unique stories about the physical and cultural environments they are from and the people who interacted with them. The problem is, many specimens are not available to the public, haven't been touched in decades, or haven't been taken care of properly. Numerous studies describe the ways that herbarium collections can give insights about the climate when they were collected, feeding habits of insects as well as showing how extinction, invasive species, and human activity have altered the general spread of plants in the wild. The goals of this research were to understand the process of how specimen labels are deciphered and entered into a database to make collections more accessible, and how specimens are repaired and preserved to maximize their utility and longevity. To achieve these goals, specimens ranging from Samoa to Italy were repaired and databased. Speaking French and Italian was useful as there were some labels in these languages. Repairing specimens required being delicate and precise, making sure not to damage them during the process, and ensuring that they were in a more stable state than before. In the end, the specimens had plenty of information to tell me when the native names and ages of specimens were present. This opens a window into the past and to other cultures which is integral to the conservation of the planet and its history. Failure to protect and preserve this information would be a tragic loss of historic information.


C-02: The Effect of UV Light Exposure on Sunflowers

Sarah Bartlett, Biological Sciences and Ballet
Project Advisor: Dr. Theresa Culley
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Awarded Excellence in Research Communication

Plants require specific wavelengths of sunlight to photosynthesize in order to survive. This research aims to investigate the impact of UV light on plant growth and flowering. Sunflower plants were grown in modern greenhouse rooms constructed of either glazing (replacing typical glass) that allows UV light through or standard greenhouse glazing that blocks UV light. Four different cultivars of Helianthus annuus sunflowers ('Sonja', 'Big Smile', 'Sunrich Orange', and 'Zohar') were grown from seed for 3 months in both types of greenhouse conditions, before being harvested. Their growth rates and dried biomass were compared within the UV-exposed and UV-blocked treatments.    Regardless of cultivar, sunflowers grown under UV light were generally shorter and had fewer nodes than plants without UV light. With the exception of the 'Sonja' dwarf cultivar, all cultivars exhibited lower total biomass under UV light than when grown under normal non-UV light conditions; this was also true for vegetation and floral biomass. In contrast, all four cultivars had higher relative growth rates when grown in the UV light than under non-UV conditions. Consequently, this means that although plants may grow faster under UV light, their height and biomass was not as great as for plants grown without exposure to UV.    The results of this research can be used to provide insight on the most ideal greenhouse construction materials as well as growth conditions for commercially sold flowering plants and crops.


C-03: Humidity Preferences in Drosophila Species

Samantha Jenkins, Biochemistry
Project Advisor: Dr. Stephanie Rollmann
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The fruit flies of the Drosophila genus are very important research organisms. Fruit flies are simple organisms with short life periods. Researching the humidity preference in Drosophila flies aids in understanding the behavior of why certain species populate different humidity environments based on the genes that are present in these organisms. I conducted two semesters of undergraduate research testing the humidity preferences within Drosophila melanogaster and between Drosophila melanogaster and Drosophila mojavensis. I did this by observing the behavior of Drosophila flies over a prolonged period of time when given the choice between two different humidity environments.


C-04: Sugar Feeding Impact on Humidity Preferences in Female Mosquitoes Shows Species-Specific Patterns

Grace Goodhart, Neuroscience - Neuropsychology Concentration
Project Advisor: Dr. Joshua Benoit
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Mosquitoes transmit many pathogens that cause deadly diseases and impact most, if not all, of the world's population, so it is vital to understand mosquito behavior and sensory processes in hopes of controlling the spread of disease. Humidity detection is important to both host-seeking and egg-laying in female mosquitoes, so this report explores how sugar diets impact humidity preferences in Aedes aegypti and Culex pipiens female mosquitoes. The mosquitoes were provided sucrose, arabinose, sorbitol, and water for five days prior to being placed in an experimental cage for a two-choice assay between high (100%) and low (75%) relative humidity (RH). After 24 hours of two-choice assay, the number of mosquitoes showing preference to each humidity was recorded for water avidity and behavioral preference index (PI) calculations for each treatment. The results showed that the effect of sugar feeding was species-specific where specific diets directly impacted subsequent avidity differently between species. These results have important implications for control of vector-borne diseases. Specific sugar diet treatments could be offered to mosquitoes, potentially reducing their ability to use humidity detection to reproduce and find hosts, thus reducing pathogen transmission.


C-05: Tick Thermal Tolerance Limits Vary Among Populations and Vary Significantly With Altitude and Latitude

Kamryn Fleming, Biological Sciences
Project Advisor: Dr. Joshua Benoit
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Understanding what determines the geographic range of species is crucial for predicting the effects of environmental change and especially for vectors that transmit diseases and may influence new host populations as they move to new locations. Winter ticks detrimentally impact moose and are increasing in many regions of the United States and Canada. To test whether environmental temperatures may limit the geographic extent of winter ticks, we measured the thermal tolerance limits of 9 tick populations distributed throughout North America. Tick larvae from gravid females were exposed to hot and cold temperatures and survival was assessed at 24 hours following exposure. We found significant differences in thermal tolerance traits among disparate tick populations. Larval thermal tolerance limits varied significantly with altitude and latitude of collection sites; despite being reared in lab conditions. Altogether, this suggests that winter tick populations may be locally adapted and therefore have uneven responses to environmental change. Our study highlights the importance of measuring physiological traits of several populations when considering the impact of environmental change on a species to account for the influence of local adaption and plasticity.


C-06: The Influence of Relative Humidity, Temperature, and Light Cycling on Winter Tick Questing at Four Geographic Locations

Hayley Prosser, Biological Sciences
Project Advisor: Dr. Joshua Benoit
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In recent years, moose populations have been declining due to an increase in winter ticks, Dermacentor albipictus, which cause anemia and hair loss in moose during feeding, leading to high mortality rates for calves. During the fall, tick larvae climb vegetation in search of a host; a behavior known as questing. Analyzing the factors that may trigger questing will narrow down the conditions when ticks are outside of protected microhabitats, and pest control efforts could be more fruitful. In this study, we measured questing in response to environmental stimuli in tick larvae from four geographic locations. Specifically, larvae were placed under varying environmental conditions, including temperature, relative humidity, and daylength. We predicted increased temperature variability and decreased relative humidity and daylength would trigger larval questing. We found no significant difference in questing in response to changes in daylength, but increased temperature variability, and lower relative humidity played an important role in triggering questing behaviors. We also found a significant difference in proportion of questing ticks depending on the collection site, hinting that endogenous molecular signals may drive this behavior. Altogether, endogenous mechanisms and environmental factors both play a key role in tick questing.


C-07: Navigation and Orientation of a Fiddler Crab

Prashanth Prabhakar, Biological Sciences
Project Advisor: Dr. John Layne
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Navigation is the process of accurately ascertaining one's position and planning then following a route. There are several fundamentally different mechanisms by which navigation is performed, and a nearly ubiquitous one is path integration, in which animals continuously measure and sum the distances and directions of their movements to create a "home vector" stored in memory, which they use to return home after foraging. It remains an open question for most animals: how, or in what form, is the home vector stored? That is, what provides the spatial basis, or coordinate system, for the direction of the vector? A particularly interesting example is fiddler crabs, which exclusively use path integration for navigating around their burrows and are therefore ideal for probing the question of the neuro-behavioral basis of the home vector. We hypothesized that the spatial basis for the vector is grounded, not in external coordinates, and not even in internal body-centered coordinates, but rather in the system that controls and stabilizes the eyes. To test this we measured body and eye movements of foraging crabs. Some foraged in a brightly lit arena with abundant contrast visible in the surround, and other crabs foraged in complete darkness. The former were hypothesized to be able to stabilize their eyes well, and the latter to stabilize their eyes poorly and experience ocular drift. Consistent with our hypothesis, the crabs with good eye stabilization will had accurate home vectors, and the crabs with poor stabilization showed vectors that drifted with their poorly stabilized


C-08: Spectral Sensitivity Underlying Visual Escape Response Behavior in Uca Pugilator, Fiddler Crabs

Jacob Yazell, Biological Sciences
Project Advisor: Dr. John Layne
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To detect color, an organism must have the ability to discriminate between different wavelengths of light. Animals can gain information through the visual system such as species recognization, sex, defensive ability, health, size, social status and much more. Uca pugilator, fiddler crabs, are an exceptional species to study what importance color vision has in organisms. Many of their individual tasks and social interactions rely on the visual system. This study evaluated the possible contribution of color detection to intraspecific signaling by measuring spectral sensitivities of this species. To do this, we developed a behavioral test apparatus that is novel for animal color sensitivity measurement. This was done by modifying an LCD screen to transmit a range of specific wavelengths. A dark, expanding disk is presented against a colored background as a looming stimulus to frighten the crab and induce a response. We have found that U. pugilator is sensitive to wavelengths between 360-535 nm previously in this study. There were two peaks of sensitivity near 361 nm and 500 nm, which is predicted by the amino acid sequence similarity of the crab's opsin found in previous studies. My role has been to test if the fiddler crabs can discriminate between 380 nm (Ultraviolet) and 525 nm (green).


C-09: Early Successional Dynamics in an Ohio Urban Wetland Habitat

Elizabeth Walsh, Spanish and Biological Sciences
Project Advisor: Dr. Danielle Winget
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Awarded Excellence in Research Communication

Urban wetlands are on the frontier of city planning and wildlife conservation. Wetlands are not only important sources of biodiversity, but offer many ecological and cultural benefits as well. A recent project in Cincinnati, Ohio included a constructed wetland inside of a park, combining conservation with urban development. However, constructed wetland habitats are not guaranteed ecological success. To assess the progress of this project, this study will track changes associated with community succession over a three month interval. These changes include species richness and biodiversity, (measured using the Shannon-Wiener index) species' abundances, and changes in soil chemistry. Data will be collected from quadrants within two locations inside the park, one inside the wetland, and the other on a nearby lawn for comparison. Changes in soil chemistry will be measured simultaneously, and will include moisture, light, temperature and total nitrogen, potassium, phosphate and magnesium concentrations. As the community evolves, the study expects to measure substantial changes across all categories. A statistically significant increase in biodiversity will serve as evidence of early succession, and support that the wetland is a healthy habitat. Changes in species composition, especially the presence of   wetland indicator species, will further validate this assessment. A lack of change could indicate that succession is stalled, and further human intervention may be necessary. In addition, the presence of volunteer species, particularly invasive species, could identify potential ecological threats. Overall, this study will provide insight into an understudied area- urban wetlands, and the important dynamics of early succession.