<p> The c^13 isotope effect in acid and alkaline hydrolysis of both ethyl and tertiary butyl benzoate-carboxyl-c^14 have been measured. Significant isotope effects were found in all the hydrolyses except acid hydrolysis of the tertiary butyl oster. These results are additional evidence for the suggestion of Choen and Schneider that alkyl oxygen rather than normal acyl oxygen bond cleavage occurs when tertiary butyl benzoate is hydrolyzed in acid solution. No appreciable c^13 isotope effect was found to occur in thermal, aqueous, or acid-catalysed decarboxylation of anthranilic acid. From this observation and other experimental evidence, it is concluded that anthranilic acid decarboxylates by a bimolecular process in which the attack of the hydrogen ion is rate controlling. It is further suggested that the hydrogen ion attack is on the zwitterion at the c carbon position. Both the c^13 and the c^14 isotope effect in the decarboxylation of mesitoic acid were measured using a mass spectrometer. The c^14 isotope effect was found to be two and one half times the magnitude of the c^13 isotope effect instead of twice as present theory predicts. </p> / Thesis / Doctor of Philosophy (PhD)

This thesis examines breastfeeding, weaning, and the post-weaning diets of 18 adults (18y+) and two subadults (aged 10y – 14y) from the rural Imperial Roman (1st – 4th c. CE) site of Vagnari, located in southern Italy. The investigation used a new method to sample dentine sections that accounts for the oblique nature of dentine development and allowed for the assignment of age categories to diagenetically altered teeth without visible dentine lines. The results indicate Vagnari children were weaned by ~3.5y, and that some males appear to have been breastfed longer than females. Despite the similar ages-at-weaning across the sample, the individuals in this study demonstrated a variety of weaning rates (i.e., speeds or paces), post-weaning dietary trends, and changes in diet across the life course. Some individuals (n = 6) appear to have been weaned rapidly, marked by significant removal of breastmilk prior to 2.5y, with small amounts of breast milk remaining in the diet until ~3.5y. Other children (n = 9) were weaned gradually, with slow, consistent removal of breastmilk until as late as 5.0y. Throughout and after the weaning period, children were fed a diet based on C3 plants and terrestrial proteins such as wheat, goat/sheep, and their by-products. A comparison of early life dentine and adult bone collagen signals for 14 individuals revealed changes in diet with increasing age, in which most people had increased access to higher terrestrial food sources such as pork and/or small amounts of marine food later in life. However, there was notable variation in dietary trends and practices across the sample, suggesting diverse dietary patterns among people from Vagnari. / Thesis / Master of Arts (MA) / In this thesis, I used samples from tooth dentine to analyze longitudinal stable isotope data for breastfeeding, weaning, and post-weaning dietary signals in a sample of 20 individuals from the Roman Imperial estate of Vagnari (1st – 4th c. CE) located in southern Italy. On average, children were weaned by ~3.5 years of age. Despite the similar age-at-weaning across the sample, individuals exhibited different weaning patterns and diversity in early life dietary practices at Vagnari. During and after weaning, the isotope data indicate that children were fed with C3 plants (e.g., wheat) and terrestrial proteins such as sheep/goat and pig. I analyzed childhood and adult diet by comparing dentine stable isotope data to bone collagen results from a sub-sample of 14 individuals. There was variability between the childhood dentine data and the adult bone collagen data, where individuals appeared to eat more pork and small amounts of fish later in life. This is the first study to explore breastfeeding and weaning practices of rural Roman children in southern Italy using stable isotope analysis of tooth dentine.

This work is concerned with the use of different "effective" nucleon-nucleon interactions in the calculation of binding energies and spectra of some of the oxygen isotopes. The variational procedure consists of using a complete set of Slater determinant wave functions, having the same total M value for the projection of the angular momentum, in order to minimize the ground states of various nucleonic configurations in.the 2s-ld nuclei. The parameters obtained are used'in the subsequent diagonalization of the Hamiltonian and its eigenvalues are interpreted as energy eigenvalues. The calculations performed in this work led to the conclusion that the density dependence of the effective force is extremely important and should not be neglected, at least in the calculation of binding energies. / Thesis / Master of Science (MS)

In rivers that shift in their natural or modified physical structure, it is expected that organisms alter their resource use with the shifts in physical changes. The Upper Mississippi River System (UMRS) is a modified river basin and stark contrasts in both the physical structure of habitat types and biological structure in the types of organisms present exist spatially. The upper reaches of the basin contain more complex habitat types than the lower reaches which suggests resource use of fishes likely differs at least between upper and lower reaches. To date, the resource use of some commercially important, invasive, and imperiled species has been studied. However, little information regarding resource use exists for most native fishes. Understanding resource use and how it differs across time and space would benefit managers of the UMRS as programs are underway to restore and manage the system. To determine how resource use of native fishes differs spatially and temporally in the UMRS, I quantified resource use of ten native fishes across six reaches of the UMRS using multiple techniques. At the largest spatial and temporal scale, I quantified the natal origins of six prey and two predatory fishes using trace element analysis. At a seasonal scale, I quantified the collective resource use of eight species using carbon and nitrogen isotopes to compare isotopic niche space, niche overlap, and community metrics. At the shortest scale, I quantified the diets of two predatory species that are thought to compete with one another. Both large scale similarities and nuances in resource use existed in the UMRS depending on the spatial and temporal contexts. At the longest scale, fishes consistently used network connectivity as tributaries and other mainstem river reaches contributed recruits to the mainstem river. However, the percentage of individuals resulting from network connectivity and the specific rivers that lent the recruits differed among species and reaches. Particularly, large tributaries like the Minnesota and Missouri rivers contributed relatively high numbers of recruits to nearby reaches compared to other tributaries, and the most downstream reaches had the greatest contributions from network connectivity. Prey fishes recruited more often from tributaries than predators whereas consumed prey and prey collected directly from the UMRS had similar origins which were consistent across years. At a seasonal scale, breadth of resource use of individual species and the assemblage and some community metrics increased whereas overlap decreased moving downstream in the UMRS. This shift in resource use metrics coincides with shifts in the physical structure of the system. At the shortest scale, diet compositions of the two predators were similar to one another and spatially among upper reaches in the UMRS. These two predators likely coexist in part due to diet plasticity and prey size allocations that differ between species. Additionally, the relative physical homogeneity of the upper reaches of the UMRS may have led to the spatial similarity in prey use. Together, these results suggest the physical structure of the system impacted the resource use of fishes, where trophic niches and use of network connectivity shifted with the shift in physical structure of the Mississippi River. At a minimum, spatial gradients in isotopic niches and percentage of individuals coming from network connectivity suggest the resource use of fishes in downstream reaches at seasonal and life-long scales differs from the upstream reaches within this system. These differences could stem from longitudinal or functional process zone shifts in the physical structure which cannot be determined given these data. In the context of management of the system, fishes use network connectivity to at least some degree across all species and sampling reaches, indicating that the connectivity in the system should at least be maintained if not improved. Additionally, fish move among reaches (i.e., through lock and dams) and tributaries, which highlights the need for interjurisdictional management not just in the UMRS but in nearby tributary systems like the Minnesota and Missouri River where fish originated.

Khirbet Summeily is an early Iron Age II site located northwest of Tell el-Hesi in Southern Israel. Excavations sponsored by the Cobb Institute of Archaeology have revealed a large structure with a potential ritual space dated to the Iron Age IIA (ca. 1000-980/850 B.C.E.). Recent interpretations suggest the site was integrated into a regional economic and political system and functioned as a potential administrative outpost based on the material culture and architecture recovered from the Iron Age IIA layers. This thesis presents the carbon, oxygen, and strontium isotopic analyses of intra-tooth samples from ovicaprine and cattle remains to test herd management strategies in connection to administrative and cultic provisioning activities. The animal remains are used as proxies to identify political and economic ties through herd management patterns. These results will test the hypothesis that Khirbet Summeily was an administrative outpost integrated into a larger political and/or economic network.

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Insect migration stands as a phenomenon of paramount ecological importance, influencing ecosystems through a myriad of mechanisms, from facilitating pollination to aiding at disease transmission. Many insect species undertake multi-generational migrations in the Afro-tropical and Palearctic ranges, and increasing evidence highlights a number of migratory circuits across the entire Afro-Palearctic. Yet unravelling the migratory connectivity of the successive generations of these insects remains challenging given the impossibility to apply traditional biologger technology (e.g., radiotelemetry, light loggers), because of the small size, short life span and often large population sizes and ranges of insects. To address this challenge, this research pioneers the application of dual stable isotopic geolocation techniques based on hydrogen (δ2H) and strontium (⁸⁷Sr/⁸⁶Sr). Isotope geolocation consists of comparing the isotopic signatures of a mobile individual (e.g., migratory insect) to a map predicting isotope variations on the landscape (i.e., isoscape). Consequently, applying isotope geolocation to reconstruct insect migratory routes and connectivity requires the development of isoscapes across the migratory circuit. We first developed a novel δ2H isoscape in insect wing tissues across the Afro-Palearctic range. We analyzed wing tissue from resident butterflies across the Afro-Palearctic. A strong linear relationship between δ2H in local known-origin butterfly wings and local growing-season precipitation δ2H values was found across the Afro-Palearctic allowing the development of a robust isoscape. However, the relationship was weaker in the Afrotropics due to the region’s unique environmental characteristics, notably highly variable evaporation rates and relative humidity. Achieving increased geolocation precision in this region will necessitate the development of novel modeling approaches, incorporating more time-specific environmental and climate data as well as combining other independent geolocation tools. To enhance the isotope geolocation potential of migratory butterflies across the Afro-Palearctic range, we developed a bioavailable strontium isoscape. Strontium isotope variations on the landscape are usually independent from those of hydrogen providing a second level of geolocation evidence and enhancing geolocation potential. To build a ⁸⁷Sr/⁸⁶Sr isoscape, we first compiled bioavailable ⁸⁷Sr/⁸⁶Sr data across the range and analyzed a series of plant samples to fill existing spatial gaps. We then applied a novel spatial interpolation ensemble machine learning approach to predict bioavailable ⁸⁷Sr/⁸⁶Sr ratios across the range. Our analysis emphasizes the influence of factors such as geology, lithology, soil properties but also desert dust and volcanic aerosol deposition on bioavailable ⁸⁷Sr/⁸⁶Sr. The novel ensemble machine learning approach outperforms the traditional random forest regression approach and provides a better assessment of spatial uncertainty to produce the most accurate and unbiased bioavailable ⁸⁷Sr/⁸⁶Sr isoscape across the Afro-Palearctic range. As a first test to demonstrate the potential of this dual δ2H-⁸⁷Sr/⁸⁶Sr geolocation approach, we applied it to study the migratory routes and connectivity of Vanessa cardui individuals collected from each side of the Sahara Desert. Dual isotope-based metrics elucidated painted lady migration across the Sahara in unprecedented detail, notably moderate population connectivity across the Sahara with dominance of latitudinal migratory trajectories, a leapfrog migration during the southern leg across the Sahara, and incremental shorter distance migration during the northern leg of the migratory cycle. The study also highlighted the important role of the Arabian Peninsula as a significant stepping-stone for individuals traveling between Europe, Africa, and Asia. Such patterns and knowledge of this species' connectivity level will help conservation practitioners better assess risks and improve conservation strategies. In conclusion, this thesis presents two novel isoscapes, each with a range of applications. The δ2H isoscape is applicable to trace regional dispersal or migration of insects across the Palearctic, including both bidirectional migration and one-way dispersive behavior. The ⁸⁷Sr/⁸⁶Sr isoscape provides a basis to study mobility across the African continent and is applicable not only to trace the mobility of terrestrial insects but also the origin of other animals, humans, and manufactured materials across Africa. Together those isoscapes considerably advance the possibility of reconstructing the mobility of migratory insects to solve novel questions as evidenced by our case study on painted ladies.