Honors Projects
Showing 391 - 400 of 662 Items

- Embargo End Date: 2025-05-16
Date: 2024-01-01
Creator: Leopold Felix Spieler
Access: Embargoed
Date: 2020-01-01
Creator: Dani Paul Hove
Access: Open access
- Comfortable locomotion in VR is an evolving problem. Given the high probability of vestibular-visual disconnect, and subsequent simulator sickness, new users face an uphill battle in adjusting to the technology. While natural locomotion offers the least chance of simulator sickness, the space, economic and accessibility barriers to it limit its effectiveness for a wider audience. Software-enabled locomotion circumvents much of these barriers, but has the greatest need for simulator sickness mitigation. This is especially true for standing VR experiences, where sex-biased differences in mitigation effectiveness are amplified (postural instability due to vection disproportionately affects women). Predictive trails were developed as a shareable Unity module in order to combat some of the gaps in current mitigation methods. Predictive trails use navigation meshes and path finding to plot the user’s available path according to their direction of vection. Some of the more prominent software methods each face distinct problems. Vignetting, while largely effective, restricts user field-of-vision (FoV), which in prolonged scenarios, has been shown to disproportionately lower women’s navigational ability. Virtual noses, while effective without introducing FoV restrictions, requires commercial licensing for use. Early testing of predictive trails proved effective on the principal investigator, but a wider user study - while approved - was unable to be carried out due to circumstances of the global health crisis. While the user study was planned around a seated experience, further study is required into the respective sex-biased effect on a standing VR experience. Additional investigation into performance is also required.

Date: 2025-01-01
Creator: Alyssa Nicole Bommer
Access: Access restricted to the Bowdoin Community

- Embargo End Date: 2026-05-18
Date: 2023-01-01
Creator: Bridget Marjorie Patterson
Access: Embargoed

Date: 2025-01-01
Creator: Runqin Chen
Access: Access restricted to the Bowdoin Community
Date: 2025-01-01
Creator: Margaret Broaddus
Access: Open access
- ABSTRACT CHAPTER I: All nervous systems are influenced by circulating hormones, which can modulate neural circuits to produce different outputs from the same set of neurons. Invertebrate models, particularly crustaceans, serve as excellent models for studying neuromodulation because they contain neural circuits that continue to generate fictive activity when dissected out of the animal. The stomatogastric nervous system (STNS) of the Jonah Crab (Cancer borealis) has long been used to study neuromodulation due to its well-characterized circuits. Even in such a compact neural network, little is known about how these circuits are modulated, and this remains a question in all animals, particularly in humans. Here we investigated the modulation of the pyloric circuit by applying bulk hemolymph to the dissected STNS preparation. The hemolymph contains all of the circulating modulators, some of which have known effects on the pyloric rhythm (though many are still unknown). Interestingly, when hemolymph is applied to the isolated STNS, the pyloric rhythm is suppressed. This is surprising given that in vivo the STNS is continually exposed to hemolymph (the STG is situated within an artery, and thus, exposed to circulating hemolymph) and the pyloric rhythm is constitutively active. Therefore, I hypothesized that there are synaptically released neurotransmitters that excite the pyloric rhythm. To test this hypothesis, we applied three different excitatory modulators – proctolin, serotonin, and oxotremorine – separately in the presence of hemolymph. I found that proctolin and oxotremorine restore the pyloric rhythm in the presence of hemolymph. However, serotonin did not consistently overcome the inhibition of hemolymph. ABSTRACT CHAPTER II: A plethora of work has begun to identify how endogenous neural and hormonal modulators interact to influence the pyloric network. Here we examined the modulation of the stomatogastric nervous system (STNS) via two excitatory endogenous modulators CabTRP Ia and corazonin. CabTRP Ia and corazonin both excite the pyloric rhythm, but in distinct ways. Preliminary data by Nusbaum and Christie from 2003 suggested that an initial corazonin application gated a stronger response to subsequent CabTRP Ia when compared the inverse application of these neuromodulators. We sought to validate this gating phenomenon, but found no significant difference between the effects of the first and second applications of CabTRP Ia. Given that these animals are wild caught and surviving in a changing oceanic environment, it is possible that this modulatory effect in the Jonah Crab has changed over the last few decades due to environmentally driven shifts in receptor expression and channel conductances.

Date: 2025-01-01
Creator: Carina Lim-Huang
Access: Access restricted to the Bowdoin Community
Date: 2025-01-01
Creator: Hamda Abdirahman Hussein, Fatima K Kunjo
Access: Open access

Date: 2025-01-01
Creator: Cara Sydney Nova Fields
Access: Access restricted to the Bowdoin Community

Date: 2025-01-01
Creator: Rhys Edwards
Access: Access restricted to the Bowdoin Community