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Articles 1 - 30 of 3859

Full-Text Articles in Physical Sciences and Mathematics

The Environment Of Glaciovolcanic Caves And Their Value As Planetary Analogues, Christian Stenner, Lee J. Florea, Linda Sobolewski, Andreas Pflitsch, Morgan Cable, Roberto Anitori, Richard E. Davis, Kathleen Graham, Glyn Williams-Jones Sep 2024

The Environment Of Glaciovolcanic Caves And Their Value As Planetary Analogues, Christian Stenner, Lee J. Florea, Linda Sobolewski, Andreas Pflitsch, Morgan Cable, Roberto Anitori, Richard E. Davis, Kathleen Graham, Glyn Williams-Jones

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.


The Ecology Of Chemosynthesis In Submerged Coastal Caves, Robert Scharping, Michael Casso, Isabel Schaal, Paul Henderson, James Garey, Matthew Charette, John Pohlman, Stefan Sievert Sep 2024

The Ecology Of Chemosynthesis In Submerged Coastal Caves, Robert Scharping, Michael Casso, Isabel Schaal, Paul Henderson, James Garey, Matthew Charette, John Pohlman, Stefan Sievert

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.


High Mountain Ecosystems And Snow Cover In A Changing Climate: For Better Or For Worse, Philippe Choler Sep 2024

High Mountain Ecosystems And Snow Cover In A Changing Climate: For Better Or For Worse, Philippe Choler

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.


Luminescence, Esr And Cl Characterisation Of Quartz Extracted From Granite Source Rocks And The Derived Sediments Used For Provenance Studies, Daniela Constantin, Aditi Dave, Serban Grecu, Zuzanna Kabacińska, Mihai Ducea, Petru Urdea, Alida Timar-Gabor Sep 2024

Luminescence, Esr And Cl Characterisation Of Quartz Extracted From Granite Source Rocks And The Derived Sediments Used For Provenance Studies, Daniela Constantin, Aditi Dave, Serban Grecu, Zuzanna Kabacińska, Mihai Ducea, Petru Urdea, Alida Timar-Gabor

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.


Revisiting The Chronology Of Loess In North America By Using Sar-Osl And Pirir Protocols, Anca Avram Sep 2024

Revisiting The Chronology Of Loess In North America By Using Sar-Osl And Pirir Protocols, Anca Avram

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.


Preliminary Analysis Of Quartz Using Scanning Electron Microscopy Techniques, Serban Constantin Grecu, Alida Timar-Gabor Sep 2024

Preliminary Analysis Of Quartz Using Scanning Electron Microscopy Techniques, Serban Constantin Grecu, Alida Timar-Gabor

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.


Hraunrásir: Exploring And Studying The Steaming Lava Tubes Of Fagradalsfjall Volcano (Iceland), Francesco Sauro, Riccardo Pozzobon, Martina Cappelletti, Bogdan P. Onac, Ana Zelia Miller, Groq Birkefeldt Moller Pedersen, Tommaso Santagata Sep 2024

Hraunrásir: Exploring And Studying The Steaming Lava Tubes Of Fagradalsfjall Volcano (Iceland), Francesco Sauro, Riccardo Pozzobon, Martina Cappelletti, Bogdan P. Onac, Ana Zelia Miller, Groq Birkefeldt Moller Pedersen, Tommaso Santagata

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.


The Ecosystem Of A Remarkable Glaciovolcanic Cave At Mount Meager, British Columbia, Canada, Christian Stenner, Kathleen Graham, Morgan Cable, Glyn Williams-Jones, Jared J. Clance, Jacob Shaffer, Jill Mikucki, Anna Szynkiewicz, Olivia Vinnes, Michael Paton, Jeremy Nash Sep 2024

The Ecosystem Of A Remarkable Glaciovolcanic Cave At Mount Meager, British Columbia, Canada, Christian Stenner, Kathleen Graham, Morgan Cable, Glyn Williams-Jones, Jared J. Clance, Jacob Shaffer, Jill Mikucki, Anna Szynkiewicz, Olivia Vinnes, Michael Paton, Jeremy Nash

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.


Hadean Recipes, Stephen Mojzsis Sep 2024

Hadean Recipes, Stephen Mojzsis

FRONTIERS UNBOUND: Exploring Extreme Environments

No abstract provided.


Hypogenic Caves Of Syracuse Area, Sicily (Italy): Geomorphological Evidence Of Co2 Degassing, Fresh-Salt Water Mixing, And Late Condensation Corrosion, Philippe Audra, Jean-Yves Bigot, Didier Cailhol, Pierre Camps, Ilenia M. D'Angeli, Hai Cheng, R. Lawrence Edwards, Fernando Gàzquez-Sanchez, Gabriella Koltai, Giuliana Madonia, Jean-Claude Nobécourt, Marjan Temovski, Marco Vattano, Jo De Waele Aug 2024

Hypogenic Caves Of Syracuse Area, Sicily (Italy): Geomorphological Evidence Of Co2 Degassing, Fresh-Salt Water Mixing, And Late Condensation Corrosion, Philippe Audra, Jean-Yves Bigot, Didier Cailhol, Pierre Camps, Ilenia M. D'Angeli, Hai Cheng, R. Lawrence Edwards, Fernando Gàzquez-Sanchez, Gabriella Koltai, Giuliana Madonia, Jean-Claude Nobécourt, Marjan Temovski, Marco Vattano, Jo De Waele

International Journal of Speleology

Many caves in Sicily have been shown to have a sulfuric acid or other hypogenic origin. We studied three caves (Palombara, Scrivilleri, Monello) near Syracuse (eastern Sicily), in an area that was strongly uplifted and faulted, creating multiple Pleistocene marine terraces. Mineralogy, stable isotopes and dating methods (paleomagnetism, U/Th) were used to characterize cave sediments, some of which were related to the initial hypogenic phase (Fe and Mn oxides, calcite spar), others were introduced by surface runoff later. Many other sediments are the result of in situ weathering, such as lime sands produced by condensation-corrosion processes on the calcarenite walls. …


Hypogene Speleogenesis In Carbonates By Cooling Hydrothermal Flow: The Case Of Mt. Berenike Caves, Israel, Roi Roded, Boaz Langford, Einat Aharonov, Piotr Szymczak, Micka Ullman, Shemesh Yaaran, Boaz Lazar, Amos Frumkin Aug 2024

Hypogene Speleogenesis In Carbonates By Cooling Hydrothermal Flow: The Case Of Mt. Berenike Caves, Israel, Roi Roded, Boaz Langford, Einat Aharonov, Piotr Szymczak, Micka Ullman, Shemesh Yaaran, Boaz Lazar, Amos Frumkin

International Journal of Speleology

The Berenike hypogenic cave system near Lake Kinneret, Israel, provides a valuable case study for investigating the recently proposed Confined-Cooling-Flow (CCF) speleogenesis model. Field and speleological surveys, along with existing research, are used to provide a thorough analysis. The CCF model relies on a simple thermo-hydro-chemical scenario, involving the rise of CO2-rich hydrothermal fluids discharging into a confined layer. The cooling of these CO2-rich fluids turns them into aggressive solutions due to the inverse relation between temperature and solubility of carbonates (retrograde solubility). Previous geochemical and numerical analyses of the CCF model predict localized and persistent dissolution and speleogenesis on …


Quantitative Reasoning: What’S Math Got To Do With It?, Pamela Burdman Jul 2024

Quantitative Reasoning: What’S Math Got To Do With It?, Pamela Burdman

Numeracy

This keynote address explores the history and role of college math requirements with a focus on ensuring math courses serve to expand students’ horizons, rather than serve as gatekeepers. It discusses the advent of general education math courses, which brought more students into math departments, which ultimately contributed to broadening the scope of the courses to align with more students’ interests and majors, since their purpose was to advance quantitative reasoning, not mathematics skill per se. It also examines several practices to address calculus’ gatekeeping role: revising placement practices and prerequisites, redesigning courses, and updating instruction and assessment practices. Lastly, …


Constraining The Evolutionary Stages Of A Hypogene Karst System By Combining Morphological, Geochemical And Geochronological Data - The Example Of Carbonate Breccia-Hosted Melnička Peštera, Marjan Temovski, Zsófia Ruszkiczay-Rüdiger, Kata Molnár, László Rinyu, Alexander Wieser, Oscar Marchhart, László Palcsu Jul 2024

Constraining The Evolutionary Stages Of A Hypogene Karst System By Combining Morphological, Geochemical And Geochronological Data - The Example Of Carbonate Breccia-Hosted Melnička Peštera, Marjan Temovski, Zsófia Ruszkiczay-Rüdiger, Kata Molnár, László Rinyu, Alexander Wieser, Oscar Marchhart, László Palcsu

International Journal of Speleology

A combination of morphological observations, geochemical data from calcite minerals and geochronology by burial age dating and U-series is used to constrain the geological and geomorphological setting and the evolutionary stages of a hypogene karst system. This methodological suit is applied to Melnička Peštera, a horizontal cave developed in carbonate breccia overlying dolomite marble in Melnica locality (N. Macedonia), where hydrothermal karst development occurred in both dolomite and calcite marble. The passage morphology of the cave, having a reverse triangle, Laughöhle cross-sections, suggests development near the water table by slowly moving waters. Calcite crusts are found throughout the cave, and …


Co2 Hypogene Speleogenesis In An Endogenic Travertine System, Mesa Del Oro, New Mexico, Usa, Victor J. Polyak, Jeffrey R. Forbes, Michael N. Spilde, Paula P. Provencio, John R. Cochran, Yemane Asmerom Jul 2024

Co2 Hypogene Speleogenesis In An Endogenic Travertine System, Mesa Del Oro, New Mexico, Usa, Victor J. Polyak, Jeffrey R. Forbes, Michael N. Spilde, Paula P. Provencio, John R. Cochran, Yemane Asmerom

International Journal of Speleology

The Mesa del Oro travertine, deposited by upwelling CO2-rich spring waters, is a large and thick mantle of calcite overlying soft Triassic Chinle Formation mudstones in western central New Mexico, USA. The travertine contains a system of small caves known as the Pronoun Cave Complex. Whut Cave is the largest known cave in the complex. While the travertine hydrologic system is no longer active, there is ample evidence that Whut Cave was formed by hypogene speleogenesis. The Whut Cave entrance is a small roughly circular shaft that descends ~four meters and intersects a linear fissure-controlled passage. Mn-oxide was …


Revealing The Ongoing Speleogenetic Processes In An Underwater Cave Through The Application Of Natural Radionuclides And Stable Isotopes: Case Study From The Hypogene Buda Thermal Karst, Anita Erőss, Katalin Hegedűs-Csondo, Petra Kovács-Bodor, Dénes Szieberth, Ákos Horváth, György Czuppon, Andrea Mindszenty Dr, Szabolcs Leél-Őssy, Judit Mádl-Szőnyi Jul 2024

Revealing The Ongoing Speleogenetic Processes In An Underwater Cave Through The Application Of Natural Radionuclides And Stable Isotopes: Case Study From The Hypogene Buda Thermal Karst, Anita Erőss, Katalin Hegedűs-Csondo, Petra Kovács-Bodor, Dénes Szieberth, Ákos Horváth, György Czuppon, Andrea Mindszenty Dr, Szabolcs Leél-Őssy, Judit Mádl-Szőnyi

International Journal of Speleology

The underwater Molnár János Cave in the hypogene Buda Thermal Karst system (Budapest, Hungary) provides a unique site to study the effects of flowing groundwater and the interplay of fluids of different origin. The aim of the present study is to characterize the groundwater in different parts of the cave with temporal resolution, hence describe the recent speleogenetic processes within the cave. This study uses natural radioisotopes (uranium, radium, and radon) besides stable isotope ratios of oxygen and hydrogen to identify the different fluid components. The results show that the majority of the cave is situated in the flow path …


Mid- To Late-Miocene Hypogene Speleogenesis Tied To The Tectonic History Of The Central Basin And Range Province, Usa, Louise D. Hose, Victor Polyak, Harvey R. Duchene, J. Douglas Powell, Leslie A. Melim, Gretchen M. Baker, Donald G. Davis, Yemane Asmerom Jul 2024

Mid- To Late-Miocene Hypogene Speleogenesis Tied To The Tectonic History Of The Central Basin And Range Province, Usa, Louise D. Hose, Victor Polyak, Harvey R. Duchene, J. Douglas Powell, Leslie A. Melim, Gretchen M. Baker, Donald G. Davis, Yemane Asmerom

International Journal of Speleology

Twenty-five caves displaying evidence of hypogene speleogenesis in White Pine County, Nevada, were studied between May 2022 and October 2023. Results demonstrate that the central Basin and Range Province is a major hypogenic cave region with speleogenesis dating back to the Middle Miocene. The U-Pb radiometric dates of cave mammillaries obtained so far cover a wide span of time, ranging between 14 Ma to 2 Ma. Tectonic shearing along the Snake Range Décollement up to about 22 Ma probably brackets the maximum age of speleogenesis. Thus, speleogenesis began between 22-14 Ma, which predates most of the Basin and Range extensional …


Role Of Hypogenesis In The Evolution Of Karst In The Taurus Mountains Range, Turkey, Serdar C. Bayari, Naciye Nur Özyurt, Lütfi Nazik, Koray A. Törk, Noyan İ. Güner, Emrah Pekkan, Pınar Avcı Jun 2024

Role Of Hypogenesis In The Evolution Of Karst In The Taurus Mountains Range, Turkey, Serdar C. Bayari, Naciye Nur Özyurt, Lütfi Nazik, Koray A. Törk, Noyan İ. Güner, Emrah Pekkan, Pınar Avcı

International Journal of Speleology

Field observations and laboratory data collected from the Taurus Mountains Range, Turkey during the last two decades provided evidence for the link between the evolution of hypogene karst and the geodynamic history. Major evidence includes; carbonate-hosted secondary ore deposits that are converted from primarily hypogene minerals by epigene, oxygen-rich groundwater circulating at local to intermediate depths. Another piece of evidence of hypogene karst in the Tauride is the Kırkgöz springs’ huge submerged cave/conduit system, which formed the Antalya Travertine Plateau, which is the world’s largest deposit precipitated by cool karst groundwater. The obruks in central Tauride are giant collapse dolines …


A Speleogenetic History Of Novoafonskaya Cave In The Western Caucasus, Olga Chervyatsova, Sergey Potapov, Jonathan Baker, Dmitry Gavryushkin, Victor Polyak, Matt Heizler, Sergey Tokarev, Sergey Sadykov, Roman Dbar, Yuri Dublyansky Jun 2024

A Speleogenetic History Of Novoafonskaya Cave In The Western Caucasus, Olga Chervyatsova, Sergey Potapov, Jonathan Baker, Dmitry Gavryushkin, Victor Polyak, Matt Heizler, Sergey Tokarev, Sergey Sadykov, Roman Dbar, Yuri Dublyansky

International Journal of Speleology

Speleogenesis in hypogene karst settings may be closely tied to regional tectonic dynamics and concomitant hydrochemical evolution of karst waters. However, placing temporal constraints on these processes can require a wider array of field observations and techniques than for typical karst systems. Herein, we present a comprehensive study of Novoafonskaya Cave (Western Caucasus, Abkhazia). The updated speleogenetic history of the cave comprises four stages: (1) the most ancient, a low-T hydrothermal (ca. 40–50°C) priming stage; (2) the main stage enabled by mixing of upwelling thermomineral and locally recharged common karst waters; (3) the late sulfuric-acid speleogenesis (SAS) stage, which left …


Monitoring Air Fluxes In Caves Using Digital Flow Metres, Claudio Pastore, Amir Sedaghatkish, Eric Weber, Nicolas Schmid, Pierre-Yves Jeannin, Marc Luetscher Jun 2024

Monitoring Air Fluxes In Caves Using Digital Flow Metres, Claudio Pastore, Amir Sedaghatkish, Eric Weber, Nicolas Schmid, Pierre-Yves Jeannin, Marc Luetscher

International Journal of Speleology

Precise measurements of airflow within caves are increasingly demanded to assess heat and mass transfers and their impacts on the karst environment, including subsurface ecosystems, hydrochemistry of karst water and secondary mineral precipitates. In this study, we introduce a new, low-cost and lightweight device adapted to monitoring air fluxes in caves which addresses the need for reliable measurements, low power consumption, durability and affordability. The device was calibrated in a wind tunnel, showing the high accuracy and precision of the device. Field-related uncertainties were further investigated in a ventilated cave to determine the effect of local airflow conditions on the …


Surmounting Challenges In Aggregating Results From Static Analysis Tools, Dr. Ann Marie Reinhold, Brittany Boles, A. Redempta Manzi Muneza, Thomas Mcelroy, Dr. Clemente Izurieta May 2024

Surmounting Challenges In Aggregating Results From Static Analysis Tools, Dr. Ann Marie Reinhold, Brittany Boles, A. Redempta Manzi Muneza, Thomas Mcelroy, Dr. Clemente Izurieta

Military Cyber Affairs

Aggregation poses a significant challenge for software practitioners because it requires a comprehensive and nuanced understanding of raw data from diverse sources. Suites of static-analysis tools (SATs) are commonly used to assess organizational security but simultaneously introduce significant challenges. Challenges include unique results, scales, configuration environments for each SAT execution, and incompatible formats between SAT outputs. Here, we document our experiences addressing these issues. We highlight the problem of relying on a single vendor's SAT version and offer a solution for aggregating findings across multiple SATs, aiming to enhance software security practices and deter threats early with robust defensive operations.


Generative Machine Learning For Cyber Security, James Halvorsen, Dr. Assefaw Gebremedhin May 2024

Generative Machine Learning For Cyber Security, James Halvorsen, Dr. Assefaw Gebremedhin

Military Cyber Affairs

Automated approaches to cyber security based on machine learning will be necessary to combat the next generation of cyber-attacks. Current machine learning tools, however, are difficult to develop and deploy due to issues such as data availability and high false positive rates. Generative models can help solve data-related issues by creating high quality synthetic data for training and testing. Furthermore, some generative architectures are multipurpose, and when used for tasks such as intrusion detection, can outperform existing classifier models. This paper demonstrates how the future of cyber security stands to benefit from continued research on generative models.


Klimchouk’S Impact On The Development Of Speleogenetic Models For Castile Evaporites: West Texas And Southeastern New Mexico, Usa, Kevin W. Stafford Apr 2024

Klimchouk’S Impact On The Development Of Speleogenetic Models For Castile Evaporites: West Texas And Southeastern New Mexico, Usa, Kevin W. Stafford

International Journal of Speleology

Due to the pioneering work of Alexander Klimchouk (2007), hypogene karst is now recognized as being complex and extensive throughout Permian strata of the greater Delaware Basin in West Texas and southeastern New Mexico (USA). Klimchouk heavily influenced our current understanding of hypogene speleogenesis in the Permian Ochoan Castile Formation where we now recognize diverse hypogene manifestations that include vertically-extensive breccia pipes, laterally-extensive blanket breccias, morphologically-varied caves, diagenetically-altered sulfates, and unique venting structures. Underlying Bell Canyon strata provide the transmissive zone for delivery and removal of solutionally aggressive fluids to the conformably overlying Castile evaporites. Current speleogenetic models indicate that …


The Effect Of Fixed Time Delays On The Synchronization Phase Transition, Shaizat Bakhytzhan Apr 2024

The Effect Of Fixed Time Delays On The Synchronization Phase Transition, Shaizat Bakhytzhan

USF Tampa Graduate Theses and Dissertations

Nature is full of synchronization phenomena, which are essential to many scientific fields like biology, chemistry, physics, and neuroscience. The Kuramoto model is a well-known theoretical model that helps explain the fundamental ideas behind synchronization dynamics [6]. Nevertheless, in practical situations, systems frequently display intrinsic latency, which can greatly impact their behavior during synchronization. This insight inspired our work, which looks at the results of adding temporal delays to the Kuramoto model. In particular, we investigate how the system’s synchronization dynamics are affected by delays. We shed light on the mechanisms underpinning synchronization in the face of temporal delays and …


Context-Aware Affective Behavior Modeling And Analytics, Md Taufeeq Uddin Apr 2024

Context-Aware Affective Behavior Modeling And Analytics, Md Taufeeq Uddin

USF Tampa Graduate Theses and Dissertations

Affective computing (AC) is a sub-domain of AI that has the potential to assist people by assessing mental states and making appropriate recommendations to patients, loved ones, caregivers, and domain experts. Humans usually produce an enormous amount of data (such as face videos) every day. One of the major challenges for affective computer vision is to efficiently deal with high volumes of data to facilitate automated model development. To cope with this challenge, we developed computer vision algorithms that measure the expressivity of the human face from video data. More precisely, the developed algorithms can map complex affect information from …


Quandle Rings, Idempotents And Cocycle Invariants Of Knots, Dipali Swain Apr 2024

Quandle Rings, Idempotents And Cocycle Invariants Of Knots, Dipali Swain

USF Tampa Graduate Theses and Dissertations

Quandles are sets with self-distributive binary operations that axiomatize the three Reidemeister movesin classical knot theory. In an attempt to bring ring theoretic techniques to the study of quandles, a theory of quandle rings analogous to the classical theory of group rings where several interconnections between quandles and their associated quandle rings have been explored. Functoriality of the construction implies that morphisms of quandle rings give a natural enhancement of the well-known quandle coloring and quandle 2 cocycle invariant of knots and links.

The dissertation is structured into two main parts. In the first part, we delve into quandle rings …


Dispersion Of Artificial Tracers In Ventilated Caves, Claudio Pastore, Eric Weber, Frédéric Doumenc, Pierre-Yves Jeannin, Marc Lütscher Apr 2024

Dispersion Of Artificial Tracers In Ventilated Caves, Claudio Pastore, Eric Weber, Frédéric Doumenc, Pierre-Yves Jeannin, Marc Lütscher

International Journal of Speleology

Artificial CO2 was used as a tracer along ventilated karst conduits to infer airflow and investigate tracer dispersion. In the karst vadose zone, cave ventilation is an efficient mode of transport for heat, gases and aerosols and thus drives the spatial distribution of airborne particles. Modelling this airborne transport requires geometrical and physical parameters of the conduit system, including the cross-sectional areas, the airflow and average air speed, as well as the longitudinal dispersion coefficient which describes the spreading of a solute. Four gauging tests were carried out in one mine (artificial conduit) and two ventilated caves (natural conduits). …


Beach Processes Controlling Erosional Hotspots And Their Influences On Beach Nourishment Performances: A Case Study Along West-Central Florida Barrier Island Beaches, Sophia Gutierrez Apr 2024

Beach Processes Controlling Erosional Hotspots And Their Influences On Beach Nourishment Performances: A Case Study Along West-Central Florida Barrier Island Beaches, Sophia Gutierrez

USF Tampa Graduate Theses and Dissertations

This study examines the long-term performance of repeated beach nourishment over an approximately 35-year period at two barrier islands, Sand Key and Treasure Island along the west-central Florida coast, USA. Five cycles of beach nourishment on Sand Key and six on Treasure Island were conducted during the study period. Three erosional hotspots were identified along a combined 14-km stretch of the nourished beach. The processes that cause the erosional hotspot were examined through numerical modeling of nearshore wave and current fields.

The most recent three nourishments since 2006 were monitored systematically by this study. Beach profiles were surveyed bimonthly to …


Comparative Analysis Of Time Series Models On U.S. Stock And Exchange Rates: Bayesian Estimation Of Time Series Error Term Model Versus Machine Learning Approaches, Young Keun Yang Apr 2024

Comparative Analysis Of Time Series Models On U.S. Stock And Exchange Rates: Bayesian Estimation Of Time Series Error Term Model Versus Machine Learning Approaches, Young Keun Yang

USF Tampa Graduate Theses and Dissertations

This study presents a comparative analysis of contemporary applications of time series models, focusing on the Bayesian approach. In contrast to many nonparametric studies, the Bayesian approach circumvents the common issue of bandwidth selection by offering systematic estimation and avoiding ad hoc methods. Specifically, we delve into the Bayesian approach for estimating the autocovariance function of a time series model’s error term. Traditional time series models often make the unrealistic assumption of a constant error term. Furthermore, models such as autoregressive conditional heteroskedasticity (ARCH) and general autoregressive conditional heteroskedasticity (GARCH) address the limitation of constant variance by assuming an autoregressive …


Iron Isotope Transformations In Saanich Inlet, Claire Onak Apr 2024

Iron Isotope Transformations In Saanich Inlet, Claire Onak

USF Tampa Graduate Theses and Dissertations

Iron (Fe) is required for many biogeochemical processes, with Fe bioavailability and chemistry being controlled by redox reactions that transform Fe between oxidation states and dissolved and particulate phases. In oxic seawater, Fe is present in the Fe(III) oxidation state, mainly as Fe oxyhydroxides. Under anoxic marine conditions, such as margin sediments under oxygen minimum zones or restricted basins with anoxic bottom water, Fe(III) is reduced to Fe(II), which is highly soluble and can be present at high concentrations ([Fe]). Fe isotope ratios (δ56Fe relative to IRMM-14) can be used to characterize Fe redox transformations, constrain Fe sources of Fe …


Thermal Ecology And Swimming Performance Of Native Tadpoles Dryophytes Femoralis In Central Florida, Jessalyn Aretz Mar 2024

Thermal Ecology And Swimming Performance Of Native Tadpoles Dryophytes Femoralis In Central Florida, Jessalyn Aretz

USF Tampa Graduate Theses and Dissertations

Urbanization and climate warming have contributed to global amphibian declines in recent decades. Amphibians are particularly vulnerable to climate and urban-induced warming because their physiological processes are dependent on temperature across all life stages, but few studies have been done on tadpole responses to warming in comparison to adult responses. The study objective was to determine how the thermal ecology and swimming performance of a native Florida tadpole varied with rearing temperature and urban level, and whether these traits are plastic or adaptive. We collected eggs from wild populations of pine woods treefrog (Dryophytes femoralis) tadpoles at an urban and …