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A Comparative Analysis Of Portable X-Ray Fluorescence Spectrometry And Stable Isotopes In Assessing Ancient Coastal Peruvian Diets, Theresa Jane Gilbertson

USF Tampa Graduate Theses and Dissertations

This dissertation explores a cross-cultural analysis of the dietary signatures of four coastal cultures of prehistoric Peru. A combination of elemental analysis based on portable x-ray fluorescence spectrometry (pXRF), testing trace elements presented in 209 individuals’ skulls representing the Nazca (38), Cañete (33), Lima (40), and Moche (98) valleys and/or cultures of the first millennium AD, is weighed in conjunction with isotope ratio mass spectrometry (IRMS) to analyze human bone collagen and bone apatite derived from a portion of the individuals represented in the Nazca, Cañete, and Lima cranial samples.

Evidence from the results of both tests are weighed using …

Corrosion Of Steel In Submerged Concrete Structures, Michael Thomas Walsh

USF Tampa Graduate Theses and Dissertations

This investigation determined that severe corrosion of steel can occur in the submerged portions of reinforced concrete structures in marine environments. Field studies of decommissioned pilings from actual bridges revealed multiple instances of strong corrosion localization, showing appreciable local loss of steel cross-section. Quantitative understanding of the phenomenon and its causes was developed and articulated in the form of a predictive model. The predictive model output was consistent with both the corrosion rate estimates and the extent of corrosion localization observed in the field observations. The most likely explanation for the observed phenomena that emerged from the understanding and modeling …

Discovery, Prevalence, And Persistence Of Novel Circular Single-Stranded Dna Viruses In The Ctenophores Mnemiopsis Leidyi And Beroe Ovata, Mya Breitbart, Bayleigh Benner, Parker Jernigan, Karyna Rosario, Laura Birsa, Rachel Harbeitner, Sidney Fulford, Carina Graham, Anna Walters, Dawn Goldsmith, Stella Berger, Jens Nejstgaard

Marine Science Faculty Publications

Gelatinous zooplankton, such as ctenophores and jellyfish, are important components of marine and brackish ecosystems and play critical roles in aquatic biogeochemistry. As voracious predators of plankton, ctenophores have key positions in aquatic food webs and are often successful invaders when introduced to new areas. Gelatinous zooplankton have strong impacts on ecosystem services, particularly in coastal environments. However, little is known about the factors responsible for regulating population dynamics of gelatinous organisms, including biological interactions that may contribute to bloom demise. Ctenophores are known to contain specific bacterial communities and a variety of invertebrate parasites and symbionts; however, no previous …

Water Column Stratification Structures Viral Community Composition In The Sargasso Sea, Dawn Goldsmith, Jennifer Brum, Max Hopkins, Craig Carlson, Mya Breitbart

Marine Science Faculty Publications

A decade-long study of viral abundance at the Bermuda Atlantic Time-series Study (BATS) site recently revealed an annually recurring pattern where viral abundance was fairly uniform in the well-mixed upper water column each winter, yet a subsurface peak in viral abundance between 60 and 100 m depth developed each summer during water column stratification (Parsons et al. 2012; ISME J 6:273–284). Building upon these findings, this study tests the hypothesis that in the well-mixed period (March), the viral communities at the surface and at 100 m depth are similar in composition, while during water column stratification (September), differences in the …