Physical Sciences and Mathematics Commons^™

Using Social Network Analysis To Measure And Visualize Student Clustering Within Middle And High Schools, Geoffrey David West

USF Tampa Graduate Theses and Dissertations

The dominant philosophy of American public schools has been to group students together based on similar characteristics. Known as tracking, high achieving students would take courses on the “college track” while others would take “career track” courses. It was not long until advocates noticed that this process unfairly advantaged affluent and White student over poor and minoritized groups. A new process called “ability grouping” took over where tracking left off, but to the same effect. It is difficult to measure the degree students are grouped together by a certain characteristic, and while a few research papers aim to do so, …

Deciphering Trends And Tactics: Data-Driven Techniques For Forecasting Information Spread And Detecting Coordinated Campaigns In Social Media, Kin Wai Ng Lugo

USF Tampa Graduate Theses and Dissertations

The main objective of this dissertation is to develop models that predict and investigate the spread of information in social media over time. In this context, we consider topics of discussions as the information that spreads. Thus, we are interested in forecasting the number of messages per day in a future interval of time. We take a data-driven approach, in which we compare our results with real datasets from a multitude of socio-political contexts and from multiple social media platforms, specifically, Twitter and YouTube.

We identified a number of challenges related to forecasting social media time series per topic. First, …

Coupling Chemical And Genomic Data Of Marine Sediment-Associated Bacteria For Metabolite Profiling, Stephanie P. Suarez

USF Tampa Graduate Theses and Dissertations

Marine sediment-associated bacteria house many new and exciting novel secondary metabolites. These metabolites can be tested for bioactivity against various types of cancer and fungal, bacterial, and viral infections. In this thesis, we investigated the combination of biosynthetic gene cluster information with mass spectra to perform a chemical profiling of sediment- associated bacteria. Furthermore, we utilized a scoring technique to provide an identification and confidence score to each annotated compound. The sediment was collected from east Arthur Harbor, Palmer Station, Antarctica, at depths of 20 ft and 60 ft. After plating on agar, 52 unique bacterial strains were isolated, with …

Coupling Chemical And Genomic Data Of Marine Sediment-Associated Bacteria For Metabolite Profiling, Stephanie P. Suarez

USF Tampa Graduate Theses and Dissertations

Marine sediment-associated bacteria house many new and exciting novel secondary metabolites. These metabolites can be tested for bioactivity against various types of cancer and fungal, bacterial, and viral infections. In this thesis, we investigated the combination of biosynthetic gene cluster information with mass spectra to perform a chemical profiling of sediment- associated bacteria. Furthermore, we utilized a scoring technique to provide an identification and confidence score to each annotated compound. The sediment was collected from east Arthur Harbor, Palmer Station, Antarctica, at depths of 20 ft and 60 ft. After plating on agar, 52 unique bacterial strains were isolated, with …

Deciphering Trends And Tactics: Data-Driven Techniques For Forecasting Information Spread And Detecting Coordinated Campaigns In Social Media, Kin Wai Ng Lugo

USF Tampa Graduate Theses and Dissertations

The main objective of this dissertation is to develop models that predict and investigate the spread of information in social media over time. In this context, we consider topics of discussions as the information that spreads. Thus, we are interested in forecasting the number of messages per day in a future interval of time. We take a data-driven approach, in which we compare our results with real datasets from a multitude of socio-political contexts and from multiple social media platforms, specifically, Twitter and YouTube.

We identified a number of challenges related to forecasting social media time series per topic. First, …

Examining Paleoshorelines In The Eastern Gulf Of Mexico: Insights On Sea Level History And Potential Areas Of Interest For Habitat Management, Catalina Rubiano

USF Tampa Graduate Theses and Dissertations

An inventory of multibeam bathymetry containing relict drowned and lithified paleoshorelines has been compiled and analyzed in the first ever shelf-wide investigation of paleo sea level indicators on the west Florida shelf (WFS). On the largest scale, the WFS is a wide and gently sloping terrain that is characterized by a carbonate-rich sediment regime. This framework coupled with the region’s tectonic stability provided a setting in which sea level changes since ~ 20 ka have been recorded to a remarkable degree of resolution in the form of paleoshorelines which formed at sea level and were subsequently drowned and preserved in …

Examining Paleoshorelines In The Eastern Gulf Of Mexico: Insights On Sea Level History And Potential Areas Of Interest For Habitat Management, Catalina Rubiano

USF Tampa Graduate Theses and Dissertations

An inventory of multibeam bathymetry containing relict drowned and lithified paleoshorelines has been compiled and analyzed in the first ever shelf-wide investigation of paleo sea level indicators on the west Florida shelf (WFS). On the largest scale, the WFS is a wide and gently sloping terrain that is characterized by a carbonate-rich sediment regime. This framework coupled with the region’s tectonic stability provided a setting in which sea level changes since ~ 20 ka have been recorded to a remarkable degree of resolution in the form of paleoshorelines which formed at sea level and were subsequently drowned and preserved in …

Developing New Strategy Toward Ruthenium And Gold Redox Catalysis, Chenhuan Wang

USF Tampa Graduate Theses and Dissertations

This dissertation mainly contains three parts: 1) The discovery of triazole-modified Ru carbene catalysts for alkene metathesis and dynamic covalent chemistry; 2) The study of ligand assisted gold oxidative addition toward aryl iodide to achieve the alkene difunctionalization; 3) Gold redox catalysis via chiral P,N-chelating ligands. In the first part, the 1,2,3-triazole coordinated ruthenium carbene complexes (TA-Ru) were reported for the first time as a new class of modified Grubbs catalyst to achieve challenging olefin metathesis at higher temperatures without catalyst decomposition. With this new TA-Ru catalyst, cross-metathesis (CM), ring-closing metathesis (RCM) and dynamic covalent chemistry (DCvC) were achieved. The …

Deep Learning-Based Automatic Stereology For High- And Low-Magnification Images, Hunter Morera

USF Tampa Graduate Theses and Dissertations

Quantification of the true number of stained cells in specific brain regions is an important metric in many fields of biomedical research involving cell degeneration, cytotoxicology, cellular inflammation, and drug development for a wide range of neurological disorders and mental illnesses. Unbiased stereology is the current state-of-the-art method for collecting the cell count data from tissue sections. These studies require trained experts to manually focus through a z-stack of microscopy images and count (click) on a hundred or more cells per case, making this approach time consuming (~1 hour per case) and prone to human error (i.e., inter-rater variability). Thus, …

Developing New Strategy Toward Ruthenium And Gold Redox Catalysis, Chenhuan Wang

USF Tampa Graduate Theses and Dissertations

This dissertation mainly contains three parts: 1) The discovery of triazole-modified Ru carbene catalysts for alkene metathesis and dynamic covalent chemistry; 2) The study of ligand assisted gold oxidative addition toward aryl iodide to achieve the alkene difunctionalization; 3) Gold redox catalysis via chiral P,N-chelating ligands.

In the first part, the 1,2,3-triazole coordinated ruthenium carbene complexes (TA-Ru) were reported for the first time as a new class of modified Grubbs catalyst to achieve challenging olefin metathesis at higher temperatures without catalyst decomposition. With this new TA-Ru catalyst, cross-metathesis (CM), ring-closing metathesis (RCM) and dynamic covalent chemistry (DCvC) were achieved. The …

Deep Learning-Based Automatic Stereology For High- And Low-Magnification Images, Hunter Morera

USF Tampa Graduate Theses and Dissertations

Quantification of the true number of stained cells in specific brain regions is an important metric in many fields of biomedical research involving cell degeneration, cytotoxicology, cellular inflammation, and drug development for a wide range of neurological disorders and mental illnesses. Unbiased stereology is the current state-of-the-art method for collecting the cell count data from tissue sections. These studies require trained experts to manually focus through a z-stack of microscopy images and count (click) on a hundred or more cells per case, making this approach time consuming (∼1 hour per case) and prone to human error (i.e., inter-rater variability). Thus, …

Affordances And Limitations Of Molecular Representations In General And Organic Chemistry, Ayesha Farheen

USF Tampa Graduate Theses and Dissertations

Molecular representations that show chemical bonding are ubiquitous in general and organic chemistry. These help in communicating chemistry concepts that are fundamental to understanding how and why molecules interact. The goal of this dissertation work is to offer an evidence-based report on the affordances and limitations of the variety of molecular representations by chemistry topic. The variety of representations investigated are chemical formula, Lewis dot structure, line-angle diagram, ball and stick, space filling, and electrostatic potential maps. Five studies were conducted with general and organic chemistry students and three key findings emerged. First, affordances and limitations of molecular representations are …

Booker Creek: Wet Season Water Quality Trends In A Florida Urban Stream, Alexandra M. Shostak

USF Tampa Graduate Theses and Dissertations

Booker Creek, a 1.9-mile stream with a 4.9-mi2 watershed, flows southeast through highly urbanized St. Petersburg, Florida, and empties into Bayboro Harbor, which connects with Tampa Bay. This study collected and analyzed water quality data for several parameters (TN, TP, nitrate-nitrite, ammonia, orthophosphate, chl-a, fecal coliform, dissolved oxygen, pH, turbidity, temperature, and salinity) every two weeks, at four different sites, during the 2022 wet season to characterize the current state and geographic variability of Booker Creek. Current creek sampling regimes, though consistent, do not sample at multiple sites along the creek. Urban streams do not display uniform water quality along …

Booker Creek: Wet Season Water Quality Trends In A Florida Urban Stream, Alexandra M. Shostak

USF Tampa Graduate Theses and Dissertations

Booker Creek, a 1.9-mile stream with a 4.9-mi2 watershed, flows southeast through highly urbanized St. Petersburg, Florida, and empties into Bayboro Harbor, which connects with Tampa Bay. This study collected and analyzed water quality data for several parameters (TN, TP, nitrate-nitrite, ammonia, orthophosphate, chl-a, fecal coliform, dissolved oxygen, pH, turbidity, temperature, and salinity) every two weeks, at four different sites, during the 2022 wet season to characterize the current state and geographic variability of Booker Creek. Current creek sampling regimes, though consistent, do not sample at multiple sites along the creek. Urban streams do not display uniform water quality along …

Affordances And Limitations Of Molecular Representations In General And Organic Chemistry, Ayesha Farheen

USF Tampa Graduate Theses and Dissertations

Molecular representations that show chemical bonding are ubiquitous in general and organic chemistry. These help in communicating chemistry concepts that are fundamental to understanding how and why molecules interact. The goal of this dissertation work is to offer an evidence-based report on the affordances and limitations of the variety of molecular representations by chemistry topic. The variety of representations investigated are chemical formula, Lewis dot structure, line-angle diagram, ball and stick, space filling, and electrostatic potential maps. Five studies were conducted with general and organic chemistry students and three key findings emerged. First, affordances and limitations of molecular representations are …

Labile Dissolved Nickel (Ni) Concentrations In The North Pacific, Calyn M. Crawford

USF Tampa Graduate Theses and Dissertations

Nickel (Ni) is an important micronutrient for phytoplankton and bacteria that serves as a required co-factor in several metalloenzymes. Despite these known biological uses, total dissolved Ni concentrations remain elevated in global surface waters, in contrast to the surface depletion commonly observed for macronutrients and other nutrient-type trace elements. A prevailing hypothesis for the muted depletion of dissolved Ni concentrations in surface waters is that dissolved Ni in seawater is not in a bioavailable form. The chemical lability of Ni in seawater provides insight into Ni speciation and bioavailability, but few measurements have been made in the open ocean to …

Understanding Controls On Spring Hydrographs In An Eogenetic Karst Aquifer In North-Central Florida, Ryan Almeqhem

USF Tampa Graduate Theses and Dissertations

Florida has one of the largest karst aquifers in the United States, with a significant portion of its water resources originating from the eogenetic karst system in north central Florida. Despite the importance of this system, eogenetic karst still needs to be studied compared to telogenetic karst. The hydrological behavior of karst aquifers is complex, with numerous factors influencing the timing, magnitude, and shape of spring hydrographs. One hypothesis, by Florea and Vacher (2006), suggests that matrix permeability is the primary control of spring hydrographs in karst systems. However, this thesis challenges this hypothesis by presenting evidence that the recharge …

Labile Dissolved Nickel (Ni) Concentrations In The North Pacific, Calyn M. Crawford

USF Tampa Graduate Theses and Dissertations

Nickel (Ni) is an important micronutrient for phytoplankton and bacteria that serves as a required co-factor in several metalloenzymes. Despite these known biological uses, total dissolved Ni concentrations remain elevated in global surface waters, in contrast to the surface depletion commonly observed for macronutrients and other nutrient-type trace elements. A prevailing hypothesis for the muted depletion of dissolved Ni concentrations in surface waters is that dissolved Ni in seawater is not in a bioavailable form. The chemical lability of Ni in seawater provides insight into Ni speciation and bioavailability, but few measurements have been made in the open ocean to …

Understanding Controls On Spring Hydrographs In An Eogenetic Karst Aquifer In North-Central Florida, Ryan Almeqhem

USF Tampa Graduate Theses and Dissertations

Florida has one of the largest karst aquifers in the United States, with a significant portion of its water resources originating from the eogenetic karst system in north central Florida. Despite the importance of this system, eogenetic karst still needs to be studied compared to telogenetic karst. The hydrological behavior of karst aquifers is complex, with numerous factors influencing the timing, magnitude, and shape of spring hydrographs. One hypothesis, by Florea and Vacher (2006), suggests that matrix permeability is the primary control of spring hydrographs in karst systems. However, this thesis challenges this hypothesis by presenting evidence that the recharge …

Tree Planting As An Adaptive Management Tool For Climate Change In Morocco, Stephanie J. Robinson

USF Tampa Graduate Theses and Dissertations

The practice of planting fruit trees to combat climate change impacts in Morocco has been growing in popularity with support from the Moroccan government and non-profit organizations. Although it is often considered a successful adaptive management tool, tree planting initiatives (TPIs) in arid lands have not been thoroughly analyzed, their management is unstandardized, and these initiatives can cause harm when trees are planted in areas that cannot support them. To implement tree planting better these TPIs need to find areas where the trees they are introducing have the best chance of survival without negatively impacting the surrounding ecosystem and human …

Tree Planting As An Adaptive Management Tool For Climate Change In Morocco, Stephanie J. Robinson

USF Tampa Graduate Theses and Dissertations

The practice of planting fruit trees to combat climate change impacts in Morocco has been growing in popularity with support from the Moroccan government and non-profit organizations. Although it is often considered a successful adaptive management tool, tree planting initiatives (TPIs) in arid lands have not been thoroughly analyzed, their management is unstandardized, and these initiatives can cause harm when trees are planted in areas that cannot support them. To implement tree planting better these TPIs need to find areas where the trees they are introducing have the best chance of survival without negatively impacting the surrounding ecosystem and human …

Book Review: Australian Caves And Karst Systems, John Webb, Susan White, Garry K. Smith, Jo De Waele

International Journal of Speleology

No abstract provided.

Evaluating Methods For Improving Dnn Robustness Against Adversarial Attacks, Laureano Griffin

USF Tampa Graduate Theses and Dissertations

Deep learning has become more widespread as advances in the field continue. As aresult, making sure deep learning is safe has become a priority. A seemingly normal image with intentional pixel changes can cause a well-trained model to misclassify the image with high confidence. Those kinds of images are called adversarial attacks. Adversarial training has been developed to defend against adversarial attacks. This thesis evaluates different adversarial training methods against a variety of adversarial attacks. The key metrics for evaluation are classification accuracy and training time. This thesis also experiments with an improvement on an existing adversarial training method, the …

Chemical Analysis Of Metabolites From Mangrove Endophytic Fungus, Sefat E Munjerin

USF Tampa Graduate Theses and Dissertations

Natural products hold a significant place in drug discovery for their abundant and unique secondary metabolites. These secondary metabolites which encompass a range of organic compounds such as alkaloids, phenols, peptides, flavonoids, polyketides, and terpenoids, can easily be exploited for drug development. Endophytic fungi, residing harmoniously with its host, have emerged as generous producers of bioactive secondary metabolites, displaying efficacy against a wide array of human pathogens, including the challenging ESKAPE pathogens.

The research explores endophytic fungi and their prospective for drug discovery and development through the synthesis of distinctive secondary metabolites. Endophytic fungus, HM13-26C-2B, collected from Honeymoon Island, Florida …

Chemical Analysis Of Metabolites From Mangrove Endophytic Fungus, Sefat E. Munjerin

USF Tampa Graduate Theses and Dissertations

Natural products hold a significant place in drug discovery for their abundant and unique secondary metabolites. These secondary metabolites which encompass a range of organic compounds such as alkaloids, phenols, peptides, flavonoids, polyketides, and terpenoids, can easily be exploited for drug development. Endophytic fungi, residing harmoniously with its host, have emerged as generous producers of bioactive secondary metabolites, displaying efficacy against a wide array of human pathogens, including the challenging ESKAPE pathogens.

The research explores endophytic fungi and their prospective for drug discovery and development through the synthesis of distinctive secondary metabolites. Endophytic fungus, HM13-26C-2B, collected from Honeymoon Island, Florida …

Evaluating Methods For Improving Dnn Robustness Against Adversarial Attacks, Laureano Griffin

USF Tampa Graduate Theses and Dissertations

Deep learning has become more widespread as advances in the field continue. As aresult, making sure deep learning is safe has become a priority. A seemingly normal image with intentional pixel changes can cause a well-trained model to misclassify the image with high confidence. Those kinds of images are called adversarial attacks. Adversarial training has been developed to defend against adversarial attacks. This thesis evaluates different adversarial training methods against a variety of adversarial attacks. The key metrics for evaluation are classification accuracy and training time. This thesis also experiments with an improvement on an existing adversarial training method, the …

Stable Isotope Analysis On Yellowfin And Blackfin Tuna Eye Lenses Reveals Life History Patterns In The Gulf Of Mexico, Kylee M. Rullo

USF Tampa Graduate Theses and Dissertations

Spatial geography, ontogenetic movement, and trophic patterns of mobile species are key elements of effective marine resource management. A number of methods are currently available for tracking movements of pelagic migratory species, including the use of conventional and electronic tags. However, tagging campaigns can take years to provide useful data, can be expensive, and only capture a portion of a fish’s lifetime. For this project, I used stable-isotopic ratios of nitrogen (δ15N) and carbon (δ13C) in metabolically inert, chronologically-layered fish-eye lenses to explore lifetime movement and trophic patterns of yellowfin tuna (Thunnus albacares) and blackfin tuna (Thunnus atlanticus) in the …

Use Of Silica Dust And Lunar Simulants For Assessing Lunar Regolith Exposure, Layzamarie Irizarry-Colon

USF Tampa Graduate Theses and Dissertations

The utilization of the lunar regolith holds immense potential for future space exploration, but the potential health risks associated with lunar regolith are a significant concern. This literature review seeks to critically assess the use of silica and lunar simulants standards and permissible exposure limits (PELs) to evaluate the adverse health effects of lunar regolith. The literature review covers an extensive analysis of existing research, health risks, toxicological properties, and physical and chemical composition associated with silica, lunar simulants, and lunar regolith by using three main sources: regulations, scholarly articles, and Kennedy Space Center (KSC) discussion. This comprehensive analysis forms …

Stable Isotope Analysis On Yellowfin And Blackfin Tuna Eye Lenses Reveals Life History Patterns In The Gulf Of Mexico, Kylee M. Rullo

USF Tampa Graduate Theses and Dissertations

Spatial geography, ontogenetic movement, and trophic patterns of mobile species are key elements of effective marine resource management. A number of methods are currently available for tracking movements of pelagic migratory species, including the use of conventional and electronic tags. However, tagging campaigns can take years to provide useful data, can be expensive, and only capture a portion of a fish’s lifetime. For this project, I used stable-isotopic ratios of nitrogen (δ15N) and carbon (δ13C) in metabolically inert, chronologically-layered fish-eye lenses to explore lifetime movement and trophic patterns of yellowfin tuna (Thunnus albacares) and blackfin tuna (Thunnus atlanticus) in the …

Use Of Silica Dust And Lunar Simulants For Assessing Lunar Regolith Exposure, Layzamarie Irizarry-Colon

USF Tampa Graduate Theses and Dissertations

The utilization of the lunar regolith holds immense potential for future space exploration, but the potential health risks associated with lunar regolith are a significant concern. This literature review seeks to critically assess the use of silica and lunar simulants standards and permissible exposure limits (PELs) to evaluate the adverse health effects of lunar regolith. The literature review covers an extensive analysis of existing research, health risks, toxicological properties, and physical and chemical composition associated with silica, lunar simulants, and lunar regolith by using three main sources: regulations, scholarly articles, and Kennedy Space Center (KSC) discussion. This comprehensive analysis forms …