Optimal foraging theory provides a suite of tools that model the best way that an animal will <br/>structure its searching and processing decisions in uncertain environments. It has been <br/>successful characterizing real patterns of animal decision making, thereby providing insights<br/>into why animals behave the way they do. However, it does not speak to how animals make<br/>decisions that tend to be adaptive. Using simulation studies, prior work has shown empirically<br/>that a simple decision-making heuristic tends to produce prey-choice behaviors that, on <br/>average, match the predicted behaviors of optimal foraging theory. That heuristic chooses<br/>to spend time processing an encountered prey item if that prey item's marginal rate of<br/>caloric gain (in calories per unit of processing time) is greater than the forager's<br/>current long-term rate of accumulated caloric gain (in calories per unit of total searching<br/>and processing time). Although this heuristic may seem intuitive, a rigorous mathematical<br/>argument for why it tends to produce the theorized optimal foraging theory behavior has<br/>not been developed. In this thesis, an analytical argument is given for why this<br/>simple decision-making heuristic is expected to realize the optimal performance<br/>predicted by optimal foraging theory. This theoretical guarantee not only provides support<br/>for why such a heuristic might be favored by natural selection, but it also provides<br/>support for why such a heuristic might a reliable tool for decision-making in autonomous<br/>engineered agents moving through theatres of uncertain rewards. Ultimately, this simple<br/>decision-making heuristic may provide a recipe for reinforcement learning in small robots<br/>with little computational capabilities.

Robots are often used in long-duration scenarios, such as on the surface of Mars,where they may need to adapt to environmental changes. Typically, robots have been built specifically for single tasks, such as moving boxes in a warehouse or surveying construction sites. However, there is a modern trend away from human hand-engineering and toward robot learning. To this end, the ideal robot is not engineered,but automatically designed for a specific task. This thesis focuses on robots which learn path-planning algorithms for specific environments. Learning is accomplished via genetic programming. Path-planners are represented as Python code, which is optimized via Pareto evolution. These planners are encouraged to explore curiously and efficiently. This research asks the questions: “How can robots exhibit life-long learning where they adapt to changing environments in a robust way?”, and “How can robots learn to be curious?”.

In this quantitative research paper, we explored the correlation between the six dimensions of motivation as part of the Self-Determination Theory spectrum and physical activity. In addition, our aim was to also see if Transcranial Direct Current Stimulation (tDCS) paired with exercise as an intervention would affect motivation to exercise over time.

In this quantitative research paper, we explored the correlation between the six dimensions of motivation as part of the Self-Determination Theory spectrum and physical activity. In addition, our aim was to also see if Transcranial Direct Current Stimulation (tDCS) paired with exercise as an intervention would affect motivation to exercise over time.

Oxymonas is a genus of Oxymonad protist found in the hindgut of drywood termites (family Kalotermitidae). Many genera of drywood termites are invasive pests globally. The hindgut microbiome of Cryptotermes brevis, the West Indian drywood termite, has not been described in detail, and only one published sequence exists of Oxymonas from C. brevis. This study aims to analyze Oxymonas sequences in C. brevis from whole gut genetic material, as well as to dissect its place in phylogenetic trees of Oxymonas and how it fits into specific and evolutionary patterns. To amplify the 18S rRNA gene Oxymonas from C. brevis, the MasterPure DNA extraction kit was used, followed by PCR amplification, followed by agarose gel electrophoresis, followed by purification of the resulting gel bands, followed by ligation/transformation on to an LB agar plate, followed by cloning the resulting bacterial colonies, and topped off by colony screening. The colony screening PCR products were then sequenced in the Genomics Core, assembled in Geneious, aligned and trimmed into a phylogenetic tree, along with several long-read amplicon sequences from Oxymonas in other drywood termites. All whole gut sequences and one amplicon from C. brevis formed a single clade, sharing an ancestor with a sister clade of Oxymonas sp. from C. cavifrons and Procryptotermes leewardensis, but the other long-read fell into its own clade in a different spot on the tree. It can be conjectured that the latter sequence was contaminated and that the C. brevis clones are a monophyletic group, a notion further corroborated by a distantly related clade featuring sequences from Cryptotermes dudleyi, which in turn has a sister taxon of Oxymonas clones from C. cavifrons and P. leewardensis, pointing toward a different kind of co-diversification of the hosts and symbionts rather than cospeciation.

Enantiomers are pairs of non-superimposable mirror-image molecules. One molecule in the pair is the clockwise version (+) while the other is the counterclockwise version (-). Some pairs have divergent odor qualities, e.g. L-carvone (“spearmint”) vs. D-carvone (“caraway”), while other pairs do not. Existing theory about the origin of such differences is largely qualitative (Friedman and Miller, 1971; Bentley, 2006; Brookes et al., 2008). While quantitative models based on intrinsic molecular features predict some structure–odor relationships (Keller et al., 2017), they cannot identify, e.g. the more intense enantiomer in a pair; the mathematical operations underlying such features are invariant under symmetry (Shadmany et al., 2018). Only the olfactory receptor (OR) can break this symmetry because each molecule within an enantiomeric pair will have a different binding configuration with a receptor. However, features that predict odor divergence within a pair may be identifiable; for example, six-membered ring flexibility has been offered as a candidate (Brookes et al., 2008). To address this problem, we collected detection threshold data for >400 molecules (organized into enantiomeric pairs) from a variety of public data sources and academic literature. From each pair, we computed the within-pair divergence in odor detection threshold, as well as Mordred descriptors (molecular features derived from the structure of a molecule) and Morgan fingerprints (mathematical representations of molecule structure). While these molecular features are identical within-pair (due to symmetry), they remain distinct across pairs. The resulting structure+perception dataset was used to build a predictive model of odor detection threshold divergence. It predicted a modest fraction of variance in odor detection threshold divergence (r 2 ~ 0.3 in cross-validation). We speculate that most of the remaining variance could be explained by a better understanding of the ligand-receptor binding process.

Black-footed ferrets have become one of the most popular conservation success stories because of the miraculous rediscovery of the species after being declared extinct and the growing population today. The stability of the species is still highly variable as the ferrets are threatened by disease, habitat fragmentation, human infringement, and the extermination of their main prey item the prairie dog. The complexity of the issue arises from negative public perceptions of prairie dogs leading to less citizen support for protection which in turn undermines progress in black-footed ferret conservation. General issues with the bureaucracy of conservation helps to delay a formal protection of species at risk which would be especially important for species that are actively being removed or exterminated by humans like the prairie dog. Careful analysis of the black-footed ferret and the prairie dog through the lenses of their natural histories, conservation histories, and modern conservation methods suggest that the public’s opinion and support is the greatest tool for the protection of species at risk because of the complexity of conservation and the rallying bureaucratic motion.