Charles E. Schmidt College of Science

Infants communicate with their caregivers in a variety of ways – even before the onset of verbal language. One of the strategies infants employ is the use of deictic gestures (i.e., index points, showing, giving) to engage in communication about external referents with their partners. Previous associations have been identified that reveal relationships between infant deictic gesturing behaviors and maternal gesturing, however the number of studies that assess maternal interactive qualities simultaneously with these gesturing behaviors is minimal. In the current study, manual data annotation was employed to explore the relationships between infant deictic gesturing frequencies, maternal deictic gesturing frequencies, global maternal behaviors (sensitivity and intrusiveness) and dyadic characteristics. Infants between the ages of 12-months and 24-months (N = 61) and their mothers participated in free-play recorded via online videoconferencing. Frequencies of initiative deictic gestures were calculated. Dyads were classified as having a “pointer” or “non-pointer” infant and mother, respectively. Several significant associations were identified, including a negative association between maternal sensitivity and maternal giving (p = .009) and a positive association between maternal sensitivity and infant index finger pointing (p = .030).

Cryptic species remain poorly studied in octopuses. Following the reinstatement of the cryptic species, Octopus americanus, suggestions that it should supplant two taxa, Octopus vulgaris types I & II, in the western central and southwestern Atlantic Ocean, respectively, had yet been investigated in southeast Florida. To delineate this species, an integrative approach including morphological assessments and phylogenetic analyses of mitochondrial (16S & COI) and nuclear (rhodopsin) genes was employed. The utility of swabbing as a minimally invasive alternative DNA sampling method to tissue was also investigated. This taxon displays similar morphological traits to O. americanus. Maximum Likelihood phylogenetic inference placed this taxon in a highly supported monophyletic group with O. americanus. Both sampling methods delineated this taxon, though tissue was more successful. These results indicate that southeast Florida’s O. vulgaris-like species represents O. americanus. Thorough species delineation approaches advance our understanding of biodiversity, evolution, and ecology, and inform management practices.

This study presents two significant investigations in the field of proton therapy, leveraging advanced Monte Carlo simulations to improve our understanding and modeling of proton beam characteristics and secondary particle dynamics. The first investigation centers on the development and validation of a Monte Carlo model tailored for the single-room Varian ProBeam pencil beam scanning system. The study begins with an in-depth simulation analysis to justify the selection of the "g4h-phy_QGSP_FTFP_BERT" physics list configuration for our TOPASSFPTI model, developed using the TOPAS 3.9 tool with a Geant4 base, version 10.07.p03. Comprehensive verification against clinical measurements in a water phantom demonstrated the accuracy of the model. A comparative analysis between the TOPASSFPTI model and a previously published TOPAS model for the Varian ProBeam system at Emory Proton Therapy Center (TOPASEmory) revealed distinct differences in the beam characteristics. Notably, the TOPASSFPTI model exhibited a closer alignment with the specific beam characterization at SFPTI, showing a strong consistency in beam energy spread (σE) and integrated depth dose distributions (IDDs), with a 98-100% agreement under 2%/2 mm γ-index criteria. Differences in lateral spot sizes were observed, with the TOPASSFPTI model showing slightly larger spot sizes compared to TOPASEmory, which aligns more closely with SFPTI’s clinical setup. Additionally, the calibration of absolute dose values indicated significant differences in the number of protons per monitor unit (MU) between the TOPASSFPTI and the clinical treatment planning system (TPS) data, with the TOPASSFPTI model consistently showing higher values.

This study examined the effectiveness of a magnetic shark deterrent, the SharkBanz® Zeppelin, and quantified the magnetic field it produces. A shark entering the magnetic field induces an electric field that is detectable by electroreceptors. This novel stimulus may deter sharks away from hooked fish. The magnitude declined rapidly with distance and reached the ambient geomagnetic field at 36-39 cm away. Zeppelin devices and non-magnetic controls were deployed with baited remote underwater video systems, and the responses of sharks were recorded. There was a significant difference between the number of sharks deterred between the Zeppelin and control. The Zeppelin deterred sharks on 22% of their approaches in the effective range, whereas the control deterred them on 2.6% of their approaches. Although the device may be effective at deterring sharks and act as a mitigation strategy for shark depredation, tests with live fish that provide more sensory stimuli are needed.

The security of the current public-key cryptographic schemes, based on integer factorization and discrete logarithm problems, is expected to be totally broken with the development of quantum computers utilizing Shor’s algorithm. As a result, The National Institute of Standards and Technology (NIST) initiated the Post-Quantum Cryptography (PQC) standardization process in 2016, inviting researchers to submit candidate algorithms that are both resistant to quantum attacks and efficient for real world applications. Researchers have since studied various aspects of the candidate algorithms, such as their security against quantum attacks and efficient implementation on different platforms.
In this thesis, we investigate the practical aspects of Post-Quantum Cryptography and contribute to several topics. First, we focus on the knapsack problem and its security under classical and quantum attacks. Second, we improve the secure biometric template generation algorithm NTT-Sec, proposing an enhanced version, NTT-Sec-R, and providing an in-depth design and security analysis. Third, we work on optimizing implementations of the post-quantum secure signature scheme LESS and polynomial inversion algorithms for code-based schemes. Finally, we analyze a proposed countermeasure for the exposure model of SIKE, the isogeny-based scheme that is a candidate in NIST’s Round 4.

After an unexpected displacement of Atlantic spotted dolphins (Stenella frontalis) from Little Bahama Bank (LBB) to Great Bahama Bank (GBB) in 2013, the LBB immigrant and GBB resident spotted dolphins were observed socially merging and initiating courtship despite previous segregation on GBB post-displacement. This project assessed the genetic integration between them. Through microsatellite analyses and genetic differentiation, reciprocal gene flow appears to be occurring between the two communities. One male was confidently assigned paternity and six males were selected as the most likely candidate males of calves. Three mottled males were designated as the most likely candidate males of calves, indicating that younger males may be reproductively successful.

Improving skills in athletic competition often requires structured guidance from coaches, who direct performers’ intentions and attention toward achieving task objectives. Traditionally, coaching follows a linear top-down model, relying on technical demonstrations, extensive verbal instructions, and corrective feedback to promote the execution of "ideal" movement patterns for improved performance. In contrast, non-linear bottom-up coaching approaches, such as differential learning (DL), intentionally introduce unconventional movement variations that may initially appear random or counterproductive. These variations encourage performers to explore the perceptual-motor landscape and disrupt established movement solutions, thereby fostering adaptability and skill development. The current study explored these considerations by investigating an alternative to the traditional action selection model of the basal ganglia (BG). The proposed model suggests that the BG mediates cortical signals from cognitive and perceptual areas to perform analog computations to generate the appropriate velocity, direction, and force output through negative feedback mechanisms. According to this model, D1 and D2receptors within the direct and indirect pathways modulate adaptive gain in velocity control by fine tuning the final motor output.

Microbial partners provide beneficial and detrimental functions to their hosts and other microbes through the exchange of metabolites and info chemicals. Developing an understanding of these micro-interactions has considerable implications for human health, agriculture, and ecosystem protection. Here, the microbial interactions of two important marine organisms: the Forcepia sp. sponge, a source of the potential anticancer compound, lasonolide A (LSA), and Pyrodinium bahamense, a dinoflagellate which produces the potent neurotoxin, saxitoxin, were investigated. Chapter 1 introduces marine microbial interactions, their importance in the function of organisms and ecosystems, and their applications in human health, agriculture and ecosystem production. Chapter 2 describes the identification and capture of the lasonolide biosynthetic pathway from a metagenomic fosmid library. This chapter also describes the assembly of the pathway into an expression vector and attempts to sustainably produce LSA through heterologous expression. Chapter 3 describes the identification and characterization of the bacterial associates of Pyrodinium bahamense, a toxin producing dinoflagellate found in the northern Indian River Lagoon. This chapter also describes potential chemical and molecular interactions occurring between P. bahamense and its associated cultivable bacteria. Chapter 4 describes the investigation into the effects microbial associates have on the physiology of P. bahamense. The completion of this work further describes microbial interactions occurring in marine environments, their influences and functions in the physiology and evolution of marine organisms, and the tools available for their investigation and utilization for human and ecosystem benefit.

The midline nuclei of the thalamus, previously characterized as “nonspecific” with undifferentiated connections with the cortex, have been shown to distribute in a specific and highly organized manner to subcortical and cortical structures. The midline thalamus consists of the paraventricular (PV) and paratenial (PT) nuclei, dorsally, and the reuniens (RE) and rhomboid (RH) nuclei, ventrally. The PV and RE nuclei have been examined to a far greater extent than either the PT or RH and have been shown to be involved in various affective and cognitive functions. Generally, PV is more associated with emotional and motivated behaviors such as arousal, feeding, drug addiction, fear, and anxiety, whereas RE is more involved in cognitive and mnemonic functions -- as RE represents a critical bridge between the medial prefrontal cortex (mPFC) and the hippocampal formation.
As afferent projections to PT have not been systemically described, we examined the input to PT comparing it with that to PV, using retrograde anatomical tracer, fluorogold (FG). We found PT and PV are almost exclusively targeted by ‘limbic’ structures of the forebrain. Whereas afferents to PT and PV originate from very similar sources, PT receives stronger input from the cortex and PV from subcortical structures. Notably, PT receives prominent input from the mPFC and orbital (ORB) cortices, two regions associated with cognitive flexibility and decision making.

Flood events are becoming more frequent and intense as time progresses, ushering in a “new normal” for life in South Florida, a life that presumably requires flood literacy for resilience. Utilizing a 45-question digital survey, flood literacy of 600 participants from Broward, Miami-Dade, Monroe, and Palm Beach counties was assessed. Using seven indices developed for this study including residency, flood terminology literacy, flood insurance literacy, floodplain literacy, flood experience, risk communication awareness, and mitigation strategies, it was found that less than 80% of participants were flood literate, with most indicating low experience with flooding and mitigation. Interaction with risk communications and consideration of flood impacts in residency decisions were indicated as moderate. Due to inconsistencies in parts of analysis, further stratification of index topics and unification of questions types would be beneficial for future iterations of this study.