Physical Sciences and Mathematics Commons^™

Constraints On Soluble Aerosol Iron Flux To The Southern Ocean At The Last Glacial Maximum, Tim M. Conway, E. W. Wolff, R. Röthlisberger, R. Mulvaney, H. E. Elderfield

School of Geosciences Faculty and Staff Publications

Relief of iron (Fe) limitation in the Southern Ocean during ice ages, with potentially increased carbon storage in the ocean, has been invoked as one driver of glacial–interglacial atmospheric CO₂ cycles. Ice and marine sediment records demonstrate that atmospheric dust supply to the oceans increased by up to an order of magnitude during glacial intervals. However, poor constraints on soluble atmospheric Fe fluxes to the oceans limit assessment of the role of Fe in glacial–interglacial change. Here, using novel techniques, we present estimates of water- and seawater-soluble Fe solubility in Last Glacial Maximum (LGM) atmospheric dust from the European …

Construction And Destruction Of Mont Pelée Volcano: Volumes And Rates Constrained From A Geomorphological Model Of Evolution, Aurélie Germa, Pierre Lahitte, Xavier Quidelleur

School of Geosciences Faculty and Staff Publications

This study presents long‐term volumes and construction rates for the Mont Conil‐Mont Pelée volcano and rate estimates at which volcanic activity creates relief. An algorithm, ShapeVolc, is used to numerically model topographic surfaces. Volcano morphology is analyzed using current digital elevation model in combination with mapped geology to produce 10 paleotopographies at the end of four constructional stages and three destructional events. Volumes of each constructional stage were estimated at about 35.2 km³, 26.2 km³, 8.3 km³, and 2.5 km³ for a total cumulative erupted volume of 72.2 km³. We estimate …

How Many Explosive Eruptions Are Missing From The Geologic Record? Analysis Of The Quaternary Record Of Large Magnitude Explosive Eruptions In Japan, Koji Kiyosugi, Charles B. Connor, Robert S. J. Sparks, Helen S. Crosweller, Sarah K. Brown, Lee Siebert, Ting Wang, Shinji Takarada

School of Geosciences Faculty and Staff Publications

Large magnitude explosive eruptions in Japan were compiled for the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database. Here we use this dataset to investigate the under-recording of Japanese explosive eruptions. We identify under-recording of Volcanic Explosivity Index (VEI) 4–5 eruptions on two timescales. Model fitting and Akaike’s information criterion (AIC and AICc) model selection suggest that these trends can be represented with the double exponential decay model, reflecting geologic processes. The time series of the recording rate of larger eruptions (VEI 6 and 7) show a slowly decreasing trend in comparison to smaller eruptions. These time series can be represented …

Quantitative Hermeneutics: Counting Forestructures On A Path From W.M. Davis To The Concept Of Multiple-Permeability Karst Aquifers, H. L. Vacher, Lee J. Florea

International Journal of Speleology

Hermeneutics is the theory of interpretation. One of its major components is recognizing prejudgments, or forestructures, that we bring to our objects of study. In this paper, we construct a historical narrative of the evolution of thinking about the role of caves in relation to groundwater flow in limestone, and we tabulate forestructures as they appear in the story. This account consists of three overlapping time periods: the before and after of an incident that repelled hydrogeologists and students of karst from each other in the middle of the 20^th century; a period, up to around the turn of …

Geographically Isolated Wetlands: Rethinking A Misnomer, David M. Mushet, Aram J. K. Calhoun, Laurie C. Alexander, Matthew J. Cohen, Edward S. Dekeyser, Laurie Fowler, Charles R. Lane, Mark C. Rains, Susan C. Walls

School of Geosciences Faculty and Staff Publications

We explore the category “geographically isolated wetlands” (GIWs; i.e., wetlands completely surrounded by uplands at the local scale) as used in the wetland sciences. As currently used, the GIW category (1) hampers scientific efforts by obscuring important hydrological and ecological differences among multiple wetland functional types, (2) aggregates wetlands in a manner not reflective of regulatory and management information needs, (3) implies wetlands so described are in some way “isolated,” an often incorrect implication, (4) is inconsistent with more broadly used and accepted concepts of “geographic isolation,” and (5) has injected unnecessary confusion into scientific investigations and discussions. Instead, we …

Peninsular Florida Stream Systems: Guidance For Their Classification And Restoration, John H. Kiefer, Joann Mossa, Kristen B. Nowak, William R. Wise, Kenneth M. Portier, Thomas Crisman

School of Geosciences Faculty and Staff Publications

This project was performed to improve understanding of key physical and ecological attributes of natural streams in peninsular Florida in order to derive a practical process-based classification system; and also to provide design aids to assist with stream restoration in rural settings. Fifty-six of the best remaining stream systems in the peninsula were selected for monitoring of more than 120 quantitative variables known to associate with key stream system processes. The sites covered a wide range of physical gradients including soil drainage condition, drainage area, and valley slope, and were observed at watershed, valley, channel and patch scales. Hierarchical cluster …

Multiscale Postseismic Behavior On A Megathrust: The 2012 Nicoya Earthquake, Costa Rica, Rocco Malservisi, Susan Y. Schwartz, Nicholas Voss, Marino Protti, Victor Gonzalez, Timothy H. Dixon, Yan Jiang, Andrew V. Newman, Jacob Richardson, Jacob I. Walter, Denis Voyenko

School of Geosciences Faculty and Staff Publications

The Nicoya Peninsula in northwest Costa Rica overlies a section of the subduction megathrust along the Middle America Trench. On 5 September 2012, a moment magnitude 7.6 megathrust earthquake occurred beneath a dense network of continuous GPS and seismic stations. Many of the GPS stations recorded the event at high rate, 1 Hz or better. We analyze the temporal and spatial evolution of surface deformation after the earthquake. Our results show that the main rupture was followed by significant afterslip within the first 3 h following the main event. The behavior of the surface displacement can be represented by relaxation …

Correction: A Novel Approach For Detection And Quantification Of Magnetic Nanomarkers Using A Spin Valve Gmr-Integrated Microfluidic Sensor, J. Devkota, G. Kokkinis, T. Berris, M. Jamalieh, S. Cardoso, F. Cardoso, Hariharan Srikanth, Manh-Huong Phan, I. Giouroudi

Physics Faculty Publications

We demonstrate the application of a spin valve giant magneto-resistance (GMR) integrated microfluidic sensor for the detection and quantification of superparamagnetic nanomarkers. A microfluidic channel containing the magnetic fluid, micro-conductors (MCs) for collection of magnetic markers and a spin valve GMR sensor for detecting the presence of magnetic stray field were integrated into a single chip and employed for detection of various concentrations of Nanomag-D beads of 250 nm diameter. The results show that the sensor is capable of detecting concentrations as low as 500 pg μl⁻¹ of Nanomag-D beads and quantifying them in a linear scale over a …

Reconstructing Paleoenvironments Of The Plio-Pleistocene Tamiami Formation Of Florida With Benthic Foraminifera, Heather Bender

USF Tampa Graduate Theses and Dissertations

There is general agreement that a range of paleodepths and environments are represented in the individual shell units of the middle Pliocene to earliest Pleistocene Tamiami Formation of southwest Florida, but maximum depths remain poorly constrained. Here, benthic Foraminifera abundances are used as a paleoenvironmental proxy to compare the upper Tamiami from quarries in Sarasota, Florida to Recent modern coastal, bay, and reef habitats of Florida, the Grand Cayman Islands, and Puerto Rico, ranging in depth from 0 to 55 meters. I used: (1) ordination techniques, including detrended correspondence analysis (DCA) and cluster analysis, to compare upper Tamiami foraminiferal assemblages …

Development And Application Of Web-Based Open Source Drug Discovery Platforms, Yuri Pevzner

USF Tampa Graduate Theses and Dissertations

Computational modeling approaches have lately been earning their place as viable tools in drug discovery. Research efforts more often include computational component and the usage of the scientific software is commonplace at more stages of the drug discovery pipeline. However, as software takes on more responsibility and the computational methods grow more involved, the gap grows between research entities that have the means to maintain the necessary computational infrastructure and those that lack the technical expertise or financial means to obtain and include computational component in their scientific efforts. To fill this gap and to meet the need of many, …

Longitudinal Profile And Sediment Mobility As Geomorphic Tools To Interpret The History Of A Fluviokarst Stream System, John Woodside, Eric Wade Peterson, Toby Dogwiler

International Journal of Speleology

The complex drainage systems within karst settings can result in atypical longitudinal profiles. Features, such as cave entrances, can be expressed as anomalous ‘bumps’ in the longitudinal profile of a stream if downcutting has continued upstream of the area in which the water is pirated to the subsurface. Horn Hollow, a fluviokarst valley located in Carter Caves State Park Resort in northeastern Kentucky, was examined for these types of features. The objectives of this study were to determine if sediment mobility can be used as a proxy for anomalous areas along the profile of the valley and if detailed cross-sections …

Application And Development Of Computational Methods In Conformational Studies Of Bio-Molecules, Aleksandra Karolak

USF Tampa Graduate Theses and Dissertations

The work presented in my dissertation focuses on the conformational studies of bio-molecules including proteins and DNA using computational approaches. Conformational changes are important in numerous molecular bioprocesses such as recognition, transcription, replication and repair, etc. Proteins recognize specific DNA sequences and upon binding undergo partial or complete folding or partial unfolding in order to find the optimal conformational fit between molecules involved in the complex. In addition to sequence specific recognition, proteins are able to distinguish between subtle differences in local geometry and flexibility associated with DNA that may further affect their binding affinities. Experimental techniques provide high-resolution details …

Investigation Of Bioactive Metabolites From The Antarctic Sponge Dendrilla Membranosa And Marine Microorganisms, Chris G. Witowski

USF Tampa Graduate Theses and Dissertations

Natural products continue to be a valuable source of compounds in research involving chemical ecology and drug discovery. Secondary metabolites are biosynthesized to benefit the host organism in its environment (feeding deterrence from predators, antibiotic properties to avoid infection, etc.) but these compounds also serve as useful scaffolds in drug discovery applications. The research herein describes both aspects of these two branches of natural products chemistry. The Antarctic sponge Dendrilla membranosa produces diterpenes, of which membranolide A, deters feeding of the predatory amphipod Gondogenia antarctica. A metabolomic study of several sponges was undertaken to determine environmental factors that govern …

Use Of Assessments In College Chemistry Courses: Examining Students' Prior Conceptual Knowledge, Chemistry Self-Efficacy, And Attitude, Sachel M. Villafañe-García

USF Tampa Graduate Theses and Dissertations

Students' retention in STEM-related careers is of great concern for educators and researchers, especially the retention of underrepresented groups such as females, Hispanics, and Blacks in these careers. Therefore it is important to study factors that could potentially influence students' decision to stay in STEM. The work described in this dissertation involved three research studies where assessments have been used in college chemistry courses to assess students' prior content knowledge, chemistry-self-efficacy, and attitude toward science. These three factors have been suggested to have an influence on students' performance in a course and could eventually be a retention factor.

The first …

Mid-Holocene Speleothem Climate Proxy Records From Florida And Belize, Anna L. Pollock

USF Tampa Graduate Theses and Dissertations

As global temperatures rise due to anthropogenic climate change, water resources, thus economies, are threatened. A geologically recent period of increased temperatures is the mid-Holocene and an investigation of its climate may allow for a better understanding of future precipitation and changes to regional water resources. The regions of interest are tropical Northern Central America and subtropical North America with Belize and Florida representing each climate zone. By reconstructing mid-Holocene climate in Florida and Belize, I hope to provide a better understanding of how increased temperatures and a reduced latitudinal temperature gradient impacts both precipitation patterns and variability. Today, drivers …

Quest Toward The Design And Synthesis Of Functional Metal-Organic Materials (Moms): A Supermolecular Building Layer Approach (Sbl), Hasnaa Mouttaki

USF Tampa Graduate Theses and Dissertations

Metal-Organic Materials (MOMs) represent an important division of coordination chemistry. They are self-assembled through the linking of metals with organic ligands. They gained their spotlight among scientists for their aptitude for design and facile synthesis via their multi-component coordination, and their readiness to functionalization. MOMs have been targeted for specific industrial and environmental applications such as gas storage, catalysis and CO₂ sequestration.

Throughout the past decade, studies have been conducted to develop systematic approaches toward the design and synthesis of functional MOMs. Their synthesis from targeted building units has facilitated their rational design and functionalization. The Molecular Building Block …

Active Tile Self-Assembly And Simulations Of Computational Systems, Daria Karpenko

USF Tampa Graduate Theses and Dissertations

Algorithmic self-assembly has been an active area of research at the intersection of computer science, chemistry, and mathematics for almost two decades now, motivated by the natural self-assembly mechanism found in DNA and driven by the desire for precise control of nanoscale material manufacture and for the development of nanocomputing and nanorobotics. At the theoretical core of this research is the Abstract Tile Assembly Model (aTAM), the original abstract model of DNA tile self-assembly. Recent advancements in DNA nanotechnology have been made in developing strand displacement mechanisms that could allow DNA tiles to modify themselves during the assembly process by …

The Evaluation And Study Of Modern Radiation Dosimetry Methods As Applied To Advanced Radiation Therapy Treatments Using Intensity Modulated Megavoltage Photon Beams, Cassandra Stambaugh

USF Tampa Graduate Theses and Dissertations

The purpose of this work is to evaluate quasi-3D arrays for use with intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) and to determine their clinical relevance. This is achieved using a Delta4 from Scandidos and ArcCheck from Sun Nuclear and the associated software. While certain aspects of these devices and software have been previously evaluated, the main goal of this work is to evaluate the new aspects, such as reconstructing dose on a patient CT set, and extending the capabilities. This includes the capability to reconstruct the dose based on a helical delivery as well as …

Aldehydic C-H Amination Reactions Via Co(Ii)-Based Metalloradical Catalysis And Construction Of Novel Chiral Meso-Amidoporphyrin Ligands, Christopher Lee Lizardi

USF Tampa Graduate Theses and Dissertations

Medium-sized organic ring synthesis poses a seemingly insurmountable challenge, and because of this it is a field under immense investigation. Heterocyclic containing medium-sized rings are common structural motifs in nature, which has caused researchers to investigate their potential biological activity and properties as materials. This research focused on the grand challenge of medium-sized heterocyclic ring synthesis, providing the synthesis community with new tools to generate these highly evasive products, while elucidating energetic and geometric properties of one of Nature's least understood organic ring systems.

Cobalt(II)-Amidoporphyrins, [Co(D₂-Por)], are an emerging class of metalloradical catalysts (MRC) which can facilitate …

Morphodynamics Of Mullet Key, West-Central Florida, Emeli Sandoval

USF Tampa Graduate Theses and Dissertations

Mullet Key is a right angle barrier island located at the mouth of Tampa Bay, west-central Florida. Based on historical shoreline data from 1873, the Gulf (west)-facing section of the beach has been dynamic illustrating large beach advances and retreats of up to 500 m on a decadal scale, while the south (channel)-facing section of the beach has shown to maintain a stable shoreline. This study focuses on the morphodynamics of the Gulf-facing beach. Since the 1920s, most of the Gulf-facing beach has been accreting except at the southern end near the Tampa Bay main channel. However, over the past …

The Speleogenesis Of Vallgornera Cave (Mallorca, Spain): A Mineralogical And Morphological Study, Jacqueline Amelia Diehl

USF Tampa Graduate Theses and Dissertations

Cova des Pas de Vallgornera (CPV) is morphologically and scientifically, the most prominent karst feature of Mallorca Island (Spain). It consists of over 74 km of passages developed within two carbonate lithologies (reef front and back reef facies) of Upper Miocene age. Two distinct cave patterns are recognized, both tightly controlled by the type of facies; spongework mazes and collapse chambers are characteristic for the reef front unit, whereas linear, fracture-guided galleries develop in the back reef carbonates. CPV is abundantly decorated with a variety of speleothems.

The overarching goal of this study is to provide evidence towards the cave's …

Dcms: A Data Analytics And Management System For Molecular Simulation, Meryem Berrada

USF Tampa Graduate Theses and Dissertations

Despite the fact that Molecular Simulation systems represent a major research tool in multiple scientific and engineering fields, there is still a lack of systems for effective data management and fast data retrieval and processing. This is mainly due to the nature of MS which generate a very large amount of data - a system usually encompass millions of data information, and one query usually runs for tens of thousands of time frames. For this purpose, we designed and developed a new application, DCMS (A data Analytics and Management System for molecular Simulation), that intends to speed up the process …

The Detection And Quantitative Analysis Of Endocannabinoids And Endogenous Fatty Acid Amides In Apis Mellifera And Tribolium Castaneum, Perry Robert Mitchell Jr.

USF Tampa Graduate Theses and Dissertations

Endocannabinoids, and the fatty acid amides from which they are a member, have garnered greater scientific interest in the last two decades due to the cannabimimetic properties of these endogenous molecules. The most well-known of these is Anandamide, which has thus far been discovered in several species of animal ranging from C. elegans, fruit flies, to bovine and humans. Because of the importance and increasing impact of these compounds a brief overview is first presented herein, with a major focus on the N-acyldopamines due to the direct impact they potentially pose to human physiology.

Secondly, the detection and …

The Relationship Between Carbon Dioxide Concentration And Visitor Numbers In The Homothermic Zone Of The Balcarka Cave (Moravian Karst) During A Period Of Limited Ventilation, Marek Lang, Jiří Faimon, Camille Ek

International Journal of Speleology

The evolution of CO₂ levels with and without human presence was studied in a selected site (Gallery Chamber) of the homothermic zone of the Balcarka Cave (Moravian Karst, Czech Republic) during the fall, a period of limited ventilation. There were recognized various factors controlling the cave CO₂ levels under different conditions in the exterior and interior. When visitors were absent, CO₂ levels were controlled by the advective CO₂ fluxes linked to cave airflows and reaching up to ~1.5x10^-3 mol s^-1. These fluxes exceed by orders of magnitude the exchanged diffusive fluxes (up to …

Thermal Fluctuations Tunneling In Doped Conjugated Polymers, Troy C. Stedman

USF Tampa Graduate Theses and Dissertations

The possibility of using conducting polymers as organic alternatives to widely used inorganic materials for thermoelectric (TE) applications has received much attention in the past few decades. Since conducting polymers are generally inefficient compared to inorganic TE materials, research into their underlying transport mechanisms is required to improve their efficiency. We use a model based on the effects of local thermal fluctuations to characterize the transport in conducting polymer composites. With this model, full linear responses for the current and electronic heat current are obtained. From these responses, the local temperature dependent conductivity, electronic contribution to the thermal conductivity, and …

Karst Porosity Estimations From Archive Cave Surveys - Studies In The Buda Thermal Karst System (Hungary), Gáspár Albert, Magdolna Virág, Anita Erőss

International Journal of Speleology

The Buda Thermal Karst System is located under the densely populated hills of Budapest. One of its caves (Pál-völgy Cave System) is the longest cave of Hungary with 30.1 km. The research was done in this area as a methodological study to estimate karst porosity parameters of aquifers or hydrocarbon reservoirs. In this study two modeling methods are demonstrated. The volumetric modeling method was primarily aimed to determine the macro-scale (>0.5 m) conduit porosity (referred as macroporosity) of the study area as percentage of the incorporating limestone and marl. This method is based on archive survey data (maps and …

Design, Synthesis And Applications Of Polymer Biomaterials, Frankie Costanza

USF Tampa Graduate Theses and Dissertations

The emergence of antibiotic resistant bacteria has prompted the research into novel kinds of antibacterial small molecules and polymers. Nature has solved this issue with the use of cationic antimicrobial peptides, which act as nonspecific antibiotics against invading species. Herein, we have tried to mimic this general mechanism in a biocompatible and biodegradable polymer micelle based on the polymerization of naturally occurring amino acids lysine and phenylalanine linked to a PEG tether. This amphiphilic structure allows for the spontaneous collapse into stable nanoparticles in solution, which contains a hydrophilic outer layer and a hydrophobic core. Our polymers have shown activity …

Sulfidic Spring In The Gypsum Karst System Of Monte Conca (Italy): Chemistry And Microbiological Evidences, Marianna Messina, Tiziana Grech, Fiorenzo Fiorenza, Alessandro Marlettta, Pietro Valenti, Salvatore Petralia

International Journal of Speleology

Monte Conca Cave is a karst system placed in Messinian evaporites, consisting of an active cave and a resurgence located on the massif of Monte Conca, Campofranco within the "Riserva Naturale Integrale di Monte Conca". A sulfidic spring is located in the terminal gallery of the cave. To characterize the physical and chemical parameters of the Monte Conca cave and of the sulfidic spring, air temperature, relative humidity, water pH, and concentrations of dissolved sulfides, nitrates and sulfates were monitored. The high sulfide consumption rate in the sulfidic spring, evaluated by a kinetic study, suggests that biotic consumption is dominant. …

Comparing Flow-Through And Static Ice Cave Models For Shoshone Ice Cave, Kaj E. Williams, Christopher Mckay

International Journal of Speleology

In this paper we suggest a new ice cave type: the “flow-through” ice cave. In a flow-through ice cave external winds blow into the cave and wet cave walls chill the incoming air to the wet-bulb temperature, thereby achieving extra cooling of the cave air. We have investigated an ice cave in Idaho, located in a lava tube that is reported to have airflow through porous wet end-walls and could therefore be a flow-through cave. We have instrumented the site and collected data for one year. In order to determine the actual ice cave type present at Shoshone, we have …

Gamma-Aapeptides As A New Class Of Peptidomimetics: Synthesis, Structures, And Functions, Haifan Wu

USF Tampa Graduate Theses and Dissertations

Peptidomimetics are synthetic oligomers that resemble the activities of peptides. Their advantages over peptides include high stability towards proteolysis and enormous chemical diversity. Over the past two decades, there have been extensive efforts to develop peptide mimics, such as beta-peptides, peptoids, D-peptides, etc. The research on peptidomimetics have led to many important applications in both medicinal and material science. In order to explore new functions, the discovery of peptidomimetics with novel frameworks is essential. We reported the synthesis and evaluation of a new class of peptidomimetics, termed as gamma-AApeptides. Previous studies of gamma-AApeptides have revealed that gamma-AApeptides are highly resistant …