Electronic Thesis or Dissertation

Climate change has intensified thermal anomalies in coral reef ecosystems, contributing to coral bleaching and decline. As corals die, reef fragmentation increases, and species interactions in the benthos change. However, it is unclear which competitive interactions may prevail and structure future reef ecosystems. The aim of this thesis was to evaluate the effect of thermal anomalies on coral reef benthic competitive interactions. Photoquadrats in southeast Florida reef sites were assessed over 15-years to generate interaction metrics and determine effects on hard coral survivorship. A state-transition model was created to predict the resultant community across 100 years with thermal scenarios concordant with the IPCC RCP 4.5 and 8.5. Interaction doubled across three thermal anomaly events and ended up mainly composed of pairwise examples between Dictyota, Halimeda, Niphates erecta, and Erythropodium caribaeorum. Century projections confirm that soft coral and sponge interactions will increase through thermal anomalies. The survival of hard corals was more successful when colonies were in permanent or intermittent interactions than when colonies were solitary (indirect interactions). Living hard corals were mostly found interacting with the macroalgae, Dictyota, and sponge Aplysina cauliformis, while corals that died were mainly in interactions with the soft coral E. caribaeorum, and sponges N. erecta, C. delitrix, D. anchorata, and Ircinia campana. Future reefs will be composed of more interactions between soft corals and sponges as thermal anomalies intensify, which will result in a patchier and flatter community.

In this dissertation, I examined employee turnover during the Great Resignation. In my methods, I used the short-form Minnesota Satisfaction Questionnaire, the Scribd Questionnaire on Employee Turnover, and additional survey questions more applicable to our modern environment. A survey was conducted using Amazon Mechanical Turk that consisted of a sample of (N=1,036) professionals from the private, public, and nonprofit sectors who were either still employed with their organizations or had turned over in their roles within the last year.
Using correlation analysis, pictograms, regression analyses, and other tests, I inspected employee turnover, job satisfaction, and their effects on the private, public, and nonprofit sectors. The significance level was set at p-value = 0.10 in all regression analyses. Findings indicated validity in the claims that job satisfaction had a significant impact on turnover during the Great Resignation, the Great Resignation is related to characteristics, such as time of life, age, and work experience, and the Great Resignation contextually provided a trigger on turnover. However, the claim that the private, public, and nonprofit sectors have an impact on turnover during the Great Resignation proved to be inconclusive. A deeper analysis of hypotheses and results, limitations, recommendations, and prospective future studies are further provided in this dissertation.

The purpose of this multi-site study is to gain an understanding of what practices principals are employing that are impacting the effectiveness of the instructional coaches, as measured by student achievement on end of year state assessments. This study looked at three Tier 3 schools in Miami Dade County Public Schools (MDCPS) that showed significant improvement in student achievement as measured by the statewide assessments. Tier 3 schools are schools in MDCPS that have been identified by the Florida Department of Education as consistently underperforming. This dissertation sought to understand what practices were implemented by the principals in these schools that the instructional coaches considered supportive of their instructional coaching.
The study participants consisted of 3 principals, 3 assistant principals, 3 coaches, and 3 teachers, for a total of 12 participants. The assistant principals were interviewed because they are tasked with supervising various content areas and as such work directly with the coaches. The teachers were interviewed because the role of coaches is to work directly with the teachers, therefore the teachers have insight into their effectives. The participants were asked to reflect on their experience either as an instructional coach or working with the instructional coach. They participated in a 30-to-45-minute interview. Additionally, the school improvement plans, and coaching logs were analyzed.

Reinforced concrete (RC) is the building block of modern architecture and industry. The failure of which is costly and dangerous. Typically made with carbon steel rebars, corrosion resistant alloys provide an alternative method of delaying failure. Stainless steels, while more expensive than carbon steels, provide excellent corrosion resistance, but less is known about the long term monitoring of corrosion activity for stainless steel than for carbon steel. This study looks at samples prepared between 2005 and 2009 using 304SS, 316SS, and 2304SS rebars, as well as SMI and Stelax stainless steel clad carbon steel reinforcements embedded in three different concrete mixes. These selected samples are split into two exposure environments, inside humidity chambers within the laboratory and outdoor exposure. Measurements reported here were made monthly over the course of 250 plus days using the Galvanostatic Pulse method, Electrochemical Impedance Spectroscopy, and a Gecor 8 device. These methods were used to determine corrosion current, isolated corrosion current density, and solution resistance.
Corrosion current density values calculated from measurements by the Galvanostatic Pulse and Electrochemical Impedance Spectroscopy method are too small to indicate corrosion, based on value ranges provided by Andrade. However, Gecor 8 corrosion current density values indicate low levels or moderate levels of corrosion for all samples compared to the Andrade’s value ranges. The area used by the Gecor is unknown, so it’s possible this is driving up the measured values.

Core-Collapse Supernovae (CCSNe) are some of the most powerful events in the universe liberating an astonishing 3×1053 ergs of the gravitational binding energy released by the collapse of the stellar core to a nascent neutron star (PNS) that is formed in these events. The visible display is capable of outshining the entire galaxy where it inhabits. Most of this energy, ~ 99%, is carried away by neutrinos of all flavors, however.
According to the favored theory of CCSNe, the production and transport of neutrinos from the dense core through the less dense mantle is believed to deposit energy in the mantle and thereby initiate the supernova explosion. Numerically modeling these events realistically to validate the model therefore requires an accurate neutrino transport algorithm coupled to sophisticated neutrino microphysics to compute the emission, transport, and energy deposition of neutrinos.
The CHIMERA code is a radiation-hydrodynamics code that has been developed to numerically model CCSNe in multiple spatial dimensions. The neutrino transport algorithm currently incorporated in CHIMERA is based upon the Multigroup Flux-Limited Diffusion (MGFLD) method. This current method basically uses only the zeroth angular moment of the Boltzmann equation and closes the system with terms dropped from the first angular moment to produce a diffusion-like equation. A flux-limiter is added to interpolate between the diffusive and free-streaming regimes, and to prevent the algorithm from computing acausal, i.e., faster than light transport, in regions where the neutrino mean free paths are large.

This experiment evaluated the effect of positively evaluative attributes on purchasing decisions by manipulating the Type of Repetition from a study phase to a test phase. Behavioral data and hemodynamic responses were measured using functional near-infrared spectroscopy (fNIRS) in 38 participants during a study task, where brand-name products and product specific attributes were processed, and during a test phase, where participants chose to purchase either new or previously processed products that were presented with either the same attribute, a different attribute, or no attribute. Results at test showed that repeating the association produced the highest accuracy in selecting the previously processed product and the highest hemodynamic activation. In contrast, presenting a different attribute at test produced the lowest accuracy and least hemodynamic activation, much like baseline. This hemodynamic difference between the same and different conditions was especially prevalent in the left hemisphere during the later time windows. These findings suggest that repeating the association biases purchase intention and produces hemodynamic repetition enhancement. In contrast, changing the association leads to interference and reduced selection of the processed product.

Epigenetic dysregulation has been implicated in oncogenesis, with post-translational histone modifications being linked to cancer progression. WSTF/BAZ1B forms chromatin-remodeling complexes with other proteins and lowers cancer survival outcomes. Treatment resistance causes >90 % of all cancer deaths. In particular, cancers develop tolerance to cisplatin-induced genotoxicity. It is hypothesized that the BAZ1B bromodomain, PHD finger, and DDT domain recognize epigenetic modifications, contributing to cisplatin resistance in cancers. To test this, the domains were expressed in Rosetta 2 BL21(DE3) and Rosetta 2 BL21(DE3) PLysS Escherichia coli strains. Soluble proteins were extracted, purified, and then analyzed using pulldown assays and modified histone peptide arrays. The DDT and PHD finger domains were found to bind to specific histone modifications with the DDT domain also displayed DNA-binding properties. Some of the identified histone modifications have known roles/correlations in normal and cancer cells, implicating BAZ1B as an agent in oncogenesis, treatment resistance, and as a therapeutic target.

Endometriosis is an inflammatory disease that affects one in ten women, where ectopic endometrial cells grow outside of the uterus. Lesions are estrogen dependent but progesterone resistant due to decreased progesterone receptor activity. This study investigated whether a combination of dienogest, a synthetic progesterone, and calcitriol, vitamin D’s active form, had an additive or synergistic effect in the therapy of endometriosis. Experiments were conducted on immortalized endometriotic epithelial (12Z) and stromal (22B) cell lines. Results revealed that the combination therapy effectively inhibited cell viability in spheroids, limited proliferation, and reduced cell migration in cell monolayers of lipopolysaccharide- induced cells. Concentrations of prostaglandin E2, a key inflammatory cytokine, were measured from the supernatants of 12Z cells. The combination did not alter CD44 and progesterone receptor levels on the surface of 12Z cells. Further testing in a mouse model is necessary to determine the
efficacy of the combination in vivo.

In this dissertation, we develop analogues to various notion in rigidity theory in the case of angular constraints. Initially, we were interested in angle dependencies. However, by defining a chromatic graph determined by the point-line incidence or angle graph of a given angularity, we were able to determine an assortment of properties. We provide a conjectured angular rigidity matroid involving count matroids, tranversal matroids, and traditional rigidity matroids. We consider realizations of chromatic graphs in R2 as well as C similar to the work in [3]. We extend the notions of pure conditions and infinitesimal motions using the chromatic rigidity matrix by applying techniques from algebra geometric as well as classical geometric results, such as Thales’ theorem. Some realizations I computed inspired curiosity in the space of realizations of angle-constrained graphs. We generate uniformly random sets of angle constraints to consider the space of realizations given these angle sets. We provide some results for the maximum number of possible realizations for some chromatic graphs on four vertices. We conclude with some directions for further research to develop our notions of angle-rigid graphs and their properties.

The mechanisms of larval fish transport have been rigorously studied in the past several decades, building foundational knowledge of key biological and environmental factors with which to inform decisions about species management. This study has been built upon information gained from previous studies to further elucidate the processes involved at the recruitment stage of larval fishes. Vertical swimming behaviors of larval fishes enable deliberate orientation within the water column to allow organisms of limited mobility greater control over their horizontal movements. Vertical accumulation patterns of larvae are found to be tightly dependent on the strength of stratification within the water column at nursery entrances, such as estuaries. Onshore currents, such as upwelling and surface intrusions, are found to be conduits for entry into these systems. This study observed and analyzed the influence of intrusions by the Gulf Stream into the Fort Pierce Inlet and the vertical accumulation patterns of late-stage larvae associated with those events. This study incorporated a well-established zooplanktonic abundance sampling technique to achieve two primary goals: (1) to analyze the vertical abundances of larval fishes in stratified flow during Gulf Stream intrusions and (2) to assess the correlation between larval influx and intrusion events. The results of this study show a significant and positive correlation between propagule pressure of larval fishes and incidence of Gulf Stream intrusion events. Whereas previous studies have primarily described the spatiotemporal aspects of larval transport in a broader sense, our findings revealed a greater layer of complexity in the mechanisms of transport by incorporating localized hydrographic features. The information gleaned from these results can inform the ecological considerations of future fisheries management and study efforts via additional understanding about the role of physical oceanographic events in a critical life stage.