Electronic Thesis or Dissertation

An efficient scalar multiplication algorithm is vital for elliptic curve cryptosystems. The first part of this dissertation focuses on a scalar multiplication algorithm based on scalar recodings resistant to timing attacks. The algorithm utilizes two recoding methods: Recode, which generalizes the non-zero signed all-bit set recoding, and Align, which generalizes the sign aligned columns recoding. For an ℓ-bit scalar split into d subscalars, our algorithm has a computational cost of ⌈⌈ℓ logk(2)⌉/d⌉ point additions and k-scalar multiplications and a storage cost of kd−1(k − 1) – 1 points on E. The “split and comb” method further optimizes computational and storage complexity. We find the best setting to be with a fixed base point on a Twisted Edwards curve using a mix of projective and extended coordinates, with k = 2 generally offering the best performance. However, k = 3 may be better in certain applications. The second part of this dissertation is dedicated to constant-time polynomial inversion algorithms in Post-Quantum Cryptography (PQC). The computation of the inverse of a polynomial over a quotient ring or finite field is crucial for key generation in post-quantum cryptosystems like NTRU, BIKE, and LEDACrypt. Efficient algorithms must run in constant time to prevent side-channel attacks. We examine constant-time algorithms based on Fermat’s Little Theorem and the Extended GCD Algorithm, providing detailed time complexity analysis. We find that the constant-time Extended GCD inversion algorithm is more efficient, performing fewer field multiplications. Additionally, we explore other exponentiation algorithms similar to the Itoh-Tsuji inversion method, which optimizes polynomial multiplications in the BIKE/LEDACrypt setup. Recent results on hardware implementations are also discussed.

Cancer is a leading cause of death in the U.S and across the world, with estimates indicating 17 million new cancer cases in 2018, 9.5 million of which resulted in death. Statistics show that in the past 20 years cancer death rates have decreased 27% due to emerging therapies. The use of chemotherapies to kill fast-growing cells in the body has become one of the most common cancer treatments in the world today. Chemotherapy-Induced Peripheral Neuropathies (CIPNs) are the most common side effects caused by chemotherapeutic agents. CIPNs have a prevalence of up to 85% in cancer patients undergoing chemotherapy. CIPNs triggered by chemotherapeutic drug use severely damage nerves branching from either the brain or spinal cord, initiating the development of acute and/or chronic symptoms. Platinum-based and taxane-based chemotherapeutics are among the most potent and versatile drugs available for combating cancer. The two of these drugs, carboplatin and docetaxel, are known to cause peripheral neuropathies and central neurotoxicity and were the focus of this project.

The role of principal supervisors has changed significantly, moving away from a focus on compliance and towards a greater emphasis on nurturing principals' instructional leadership skills. As a result of this evolution, there is now an increased presence of supervisors in schools, but there are no clear guidelines for their activities. This study aims to fill this gap by developing a theory that explains how principal supervisors can effectively support principals in their roles. The insights gained from this study will have significant implications for the future training and professional development of principal supervisors, which aims to improve the effectiveness of principal leadership and, in turn, enhance student outcomes.
The study seeks to answer the key research question: "How do principal supervisors and their principals perceive how principal supervisors provide effective support?" Using a qualitative approach and grounded theory design, the study collected data through 15 semi-structured interviews involving three principal supervisors and 12 principals who had worked together for at least three years. The resulting grounded theory outlines a comprehensive framework that explains how principal supervisors can offer impactful support to principals.

In 2022, there were about 4,276,000 referrals to Child Protective Service (CPS) agencies within the United States in regard to 7,530,000 children (U.S. Department of Health & Human Services 2024: xii). Of these allegations there are 558,899 victims of child maltreatment (U.S. Department of Health & Human Services 2024: xii). One risk factor for child maltreatment is having a caregiver who has experienced victimization. Although there are many other risk factors for child maltreatment, this research highlights a caregiver having been maltreated and then the type of maltreatment experienced (either physical abuse or sexual abuse) as main areas of study. Results highlight that both physical and sexual abuse are found to increase the risk for other forms of maltreatment, while physical abuse increases the risk for both physical abuse and other forms of maltreatment. This research also continues by examining the type of maltreatment experienced and a child’s likelihood to engage in specific types of deviant behavior (petty, non-violent, and violent delinquency). Results show that physical abuse, sexual abuse, neglect, and emotional abuse increase the risk for petty and non-violent delinquency (partaking in criminal actions). Neglect, emotional abuse, and drug or alcohol abuse increase the risk of having been arrested by age 18.

Quantum tetrahedron is a key building block in the theory of Loop Quantum Gravity (LQG) and plays a crucial role in the boundary states of the spinfoam amplitude of LQG. In LQG with vanishing cosmological constant, the physical Hilbert space of the quantum at tetrahedron is the 4-valent SU(2) intertwiner space labeled by irreducible representation, each assigned to a face of the quantum at tetrahedron. Furthermore, the space is the solution space of the quantum at closure condition. The area spectrum of each face of the quantum at tetrahedron is discrete and is characterized by a spin label. Classically, the correspondence between a set of solutions of at closure condition and at tetrahedron is guaranteed by the Minkowski theorem. This theorem has been generalized to the curved case, where a curved closure condition applies. The curved Minkowski theorem allows us to reconstruct homogeneously curved tetrahedra (spherical or hyperbolic tetrahedra) from a family of four SU(2) holonomies that satisfy the curved closure condition Although the quantization of the closure condition for a at tetrahedron has been extensively studied in LQG, the quantization of the curved closure condition and curved tetrahedron has not been explored yet. The homogeneously curved tetrahedron has played an important role in the recent construction of the spinfoam model with cosmological constant in 3+1 dimensional LQG. It is anticipated that the quantization of a curved tetrahedron should deFIne the building block for the boundary Hilbert space of the spinfoam model.

Sourcing sediment from adjacent inlets for placement on eroded downdrift beaches is an increasingly common practice, as an inlet sources’ proximity to a placement site reduces the transportation cost of a project and is considered a beneficial use of the dredge material (BUDM). This project aimed to compare two nourishment projects using adjacent inlet sediment sources for changes in water quality, morphology, and sedimentology at two geographically similar locations in southeast Florida. In 2023, Jupiter Beach Park (Jupiter, FL) and South Inlet Park Beach (Boca Raton, FL) were nourished using sediment from the adjacent inlet system. Jupiter was nourished with sediment from the inlet’s sand trap and Boca Raton was nourished with sediment from the ebb shoal. Suspended sediment concentration (SSC) in the water column is closely associated with other properties of water including temperature, salinity, and dissolved oxygen.
A sudden increase in suspended sediment in nearshore water can be triggered by anthropogenic activity, like nourishment, as well as natural occurrences, like storms. Sampling began prior to the initiation of nourishment (February) and continued throughout hurricane season (May – November). Sediment samples were analyzed for moment method statistics (i.e., mean, standard deviation/sorting) at half-phi intervals above 63μm. Fine sediment (<63μm) was dried and weighed. Surface and bottom water samples were collected and measured for SSC, dissolved oxygen, temperature, and salinity to analyze changes in response to nourishment.

Transitions in care have been a national priority for decades to promote the safe and timely passage of patients between levels of healthcare and across care settings. Improving hospital discharge processes is an important quality improvement initiative to reduce adverse outcomes, and thirty-day readmission rates and increase patients’ satisfaction after discharge. This qualitative design study explored the perceptions, experiences, and gaps in understanding the needs of the resident and family in the transition from a hospital to a skilled nursing facility (SNF). It is essential to understand the perspective of the residents, families, and healthcare professionals who experience this transitional process to inform future research, and practice initiatives and to effectively prepare the residents and families for this transition. The purposive sample included 15 residents, 13 family members, and 12 SNF staff. The setting was a SNF within a continuing care residential community with an 89-licensed-bed capacity in Palm Beach County, FL. This doctoral research applied a descriptive qualitative methodology to capture the essence of the perceptions of residents, families, and staff participants transitioning from acute care to a skilled nursing facility. Interviews were qualitatively analyzed with an interactive model utilizing open, pattern, and thematic coding, and data (network) display to help organize, inform, and justify conclusions and explanations. Overall, 53% of residents, and 62% of families expressed confusion, frustration, concern, uncertainty, disappointment, and stress.

No group was more physically vulnerable to the COVID-19 pandemic than older adults. However, differing life histories and structural realities make for widely varying pandemic experiences. Using a life course approach, this study situates the COVID-19 pandemic and use of communication tools into context of older adults’ life experience with disasters and technology. Merging the scholarly fields of disaster sociology and aging studies, the purpose of this research is to find how life course experience and technology use impacted older adults’ perception of, and response to, COVID-19. Accordingly, I ask how does previous disaster experience and technology usage influence older adults’ coping regarding aging and crisis? Using 29 semi-structured interviews and two focus groups with older adults, I find that the political economic context in which a person experiences disaster has reverberations decades later. This can trigger a process of cumulative advantage, and that men and women have different access points to that process dependent on that context. Moreover, older adults make crisis-based decisions anchored in their current circumstances, not consciously in response to prior experience. In addition, early experience with technology, especially through work, helps to establish a solid foundation for resilience both in terms of resources and adaptation. I found the participants in this study to be remarkably resilient during the COVID-19 pandemic as a result of either earlier disaster experience, opportunities through work and relationships, and their ability to technologically adapt.

There has been substantial progress in cancer research that has markedly enhanced patient outcomes. However, chemotherapy resistance persists and often leads to multidrug resistance, rendering cancer cells unresponsive to multiple chemotherapy drugs, presenting a significant challenge in the effective treatment of the disease. Dysregulation in gene expression patterns caused by abnormalities in epigenetic mechanisms have been identified as contributing factors to the development and progression of cancer. Epigenetic research offers potential to discover drugs that target specific epigenetic modifications to regulate gene expression patterns in the context of chemotherapy resistance. I hypothesize that histone modifications on histone H3 and histone H4 contribute to doxorubicin resistance. The data presented here provides an initial screening of the mutant monoallelic histone yeast strains to identify post-translationally modifiable amino acids in H3 and H4 that could contribute to doxorubicin resistance. The possible targets of histone modifications were then repeated in triplicate to obtain statistical significance. Finally, Western blot techniques were used to identify the modification occurring on the histone H3 and histone H4 amino acid sites that were previously identified to be statistically significant.

The distribution and intensity of hypoxia (low dissolved oxygen, DO) is increasing due to eutrophication and algal blooms in estuaries like those in the Gulf of Mexico and the Indian River Lagoon. The objective of this study is to determine how low DO affects the development and lipid utilization of the Florida Pompano (Trachinotus carolinus) and Red Drum (Sciaenops ocellatus). Fertilized eggs were incubated in two DO hypoxia treatments: severe (20% DO saturation, 1.6 mg/L), moderate (50% DO saturation, 3.9 mg/L), and normoxia (100% DO saturation, 7.6 mg/L). Eggs and larvae were sampled at 24-hours post-fertilization to assess hatch survival, larval development, and fatty acid (FA) lipids utilization. Results suggest hypoxia significantly impacts Florida Pompano development, with polar FAs most affected, while Red Drum shows greater tolerance to low DO. These findings provide insight into early fish larval stages to improve conservation and management strategies for their recruitment.