The isotopic ratios S33/S32, S34/S32 and S36/S32 of different forms of sulphur in a number of meteorites have been studied. The results obtained indicate that processes of chemical fractionation have occurred in some meteorites but that the isotopic composition of the total sulphur in a single meteorite is remarkably constant from meteorite to meteorite. The relationships between the S33, S34 and S36 isotope abundances indicate that variations in these abundances due to inhomogeneities in the processes of nucleo-synthesis are not detectable. Isotopic analysis of sulphur from the iron phase of the Clark County, Pinon and Tlacotepic meteorites has shown the presence of cosmic ray induced spallation S36 and S33. These spallation results are in reasonable agreement with predictions based on production rates of other nuclei. / Thesis / Doctor of Philosophy (PhD)

This thesis applies stable isotope analysis to the study of diet from a rural Roman estate, Vagnari (1st – 4th centuries AD), in southern Italy. The major objectives of this research are to identify the types of food eaten in the Vagnari skeletal sample from stable isotope ratios, as well as to explore individual variation in diet in the sample. Isotopic composition of collagen and carbonate indicate a diet heavy in C₃ plants with the incorporation of some animal-based proteins. Isotopes of carbon from collagen (δ¹³C) were relatively consistent across the sample, with some variation according to burial type. Nitrogen (δ¹⁵N) values varied with age-at-death and the number of grave goods buried with an individual, suggesting possible status-based variation in diet. Carbon isotopes from carbonate (δ¹³Cₐₚ) suggested variation in total diet with increased age-at-death. Isotope ratios from Vagnari were also compared with other Imperial Italian sites to situate the diet within a broader Roman context. Isotopically, diets at Vagnari were most similar to other inland and rural sites, and distinct from coastal urban diets based on marine fish. These results indicate the diversity in foods eaten in the Roman Empire, both at a local site level and between different settlements. Studying diet from Vagnari provides another window into the lives of people who lived and worked on industrial estates, and bolsters knowledge of the diets of rural residents, which are underrepresented in the literature. / Thesis / Master of Arts (MA)

Calcium phosphates are important compounds as they exist in natural aqueous systems such as rivers, lakes, ocean, and soil. These calcium phosphates are widely used to provide information on paleotemperatures as well as many anthropological features, such as paleodiets. One of the most ubiquitous forms of calcium phosphate is hydroxyapatite (Ca10(PO4)6(OH)2) which is a major component of hard tissue such as bones, fossils, and tooth enamel. The oxygen isotope systematics in the hydroxyapatite associated with carbonate-water system will provide further information to allow for the reconstruction of terrestrial and marine environments. For example, Fricke et al. (1998) used oxygen isotope analysis of the carbonate components of hydroxyapatite in tooth enamel of mammals to investigate changes in terrestrial climate. Therefore, the purpose of this research study was to examine the oxygen isotope systematics in inorganic carbonate-bearing hydroxyapatite and water at low temperatures. This Master’s thesis followed and modified the methods described in Lécuyer et al. (2010) in an attempt to synthesize hydroxyapatite crystals and carbonate-bearing hydroxyapatite. The crystals synthesized were characterized in terms of several conditions (i.e., influence of mixing rate and maturations, pH, and concentrations of NaHCO3). Methods to produce hydroxyapatite were developed and analyzed using X-Ray diffraction analysis. The results demonstrated a strong dependence of pH in the hydroxyapatite solutions. Moreover, the effect of concentrations of NaHCO3 was deemed to be essential in order to obtain the desired amount of structural carbonates in the hydroxyapatite crystals. Furthermore, this research evaluated the temperature dependence of oxygen isotopic fractionation between HAP-bound carbonate and water at 10, 25, and 40 oC. Our study is the first to assess the two mixing-rates experiments with different maturations (7 and 14 days) on the oxygen isotope effects and fractionation behaviour between HAP-bound carbonate and water. Both maturation time and the effect of initial concentration of NaHCO3 were found to be the most important in determining the equilibrium conditions in our experiments. / Dissertation / Master of Science (MSc)

<p> An important issue in the study of conflict behavior concerns the manner in which one party involved in a conflict situation, can influence his protagonist to resolve the conflict in a way Which is mutually rewarding (i.e. cooperative). The present thesis is addressed to this issue. In order to study the relationship between preasymptotic interaction patterns and stable states of cooperation and conflict, the data from a. variety of two-person, mixed motive games are organized such that: a} criteria are established for defining stable states of cooperation and conflict; b) preasymptotic interaction patterns are clearly distinguished from these stable, asymptotic states; and c) the role of each dyad member is considered separately. </p> <p> Organizing the data in the manner outlined above allows the description of strategies used by real subjects Which lead to high levels or cooperation and conflict. Dyads who attain a high level or cooperation are found to use a cautious trust strategy. This strategy consists of two components, a cooperative signalling component and a firmness component. The cooperative signalling component is operationalized in terms of the difference in the proportion or cooperative choices between one dyad member and the other. The firmness component is operationalized in terms of the level of retaliation against an uncooperative action (D reciprocity). Dyads who attain a high level or conflict. are characterlzed by an inappropriate signalling compcinent, and/or the absence of a firmness component. Data are presented which indicate how the requirements for a successful cooperative signalling component vary as a function of other variables. </p> <p> The implications of focusing on stable outcomes in a conflict situation, and organizing the data in the manner developed here, are discussed in terms of notions current in the psychological literature on conflict behavior. Data from the present thesis are used to argue that strategic variables are relatively more important factors in determining stable outcomes in a particular conflict situation, than either predispositional or personality factors. </p> / Thesis / Doctor of Philosophy (PhD)

In modern populations, adolescence is recognized as a pivotal part of the life course, but bioarchaeologists have not yet widely considered the experiences of adolescents in the past. This research investigates the biological and social changes during Roman adulescentia for individuals buried at Isola Sacra (1st-4th centuries CE; Italy) and Lisieux-Michelet (4-5th centuries CE; France). To investigate biological changes, this thesis identifies osteological indicators of pubertal timing and peptide analysis to assess biological sex for pre-pubertal individuals (n=264). Results demonstrate that adulescentia experienced an extended period of puberty, from nine to 20 years of age; menarche occurred around 15 years of age. Comparisons between the two archaeological sites demonstrate similar patterns of pubertal timing, suggesting similar exposure to Early Life Stress. To investigate the social changes, this research uses stable isotope analysis of incremental dentine sections in teeth, to investigate dietary change between childhood, adolescence, and adulthood. Incorporating literary sources, observed changes in diet are contextualized in relation to expected social age changes for middle-class individuals within the Roman Empire. At both sites, females exhibit a gradual dietary transition, reflecting a gradual social age change, or that diet is not an appropriate proxy for social age changes for women. For males, changing dietary patterns correspond with the beginning of adulescentia, when these young men took on new roles within their communities and underwent pubertal development. This research demonstrates that adulescentia was an extended period of biological and social change for males and females, which took on different forms depending on one’s sex/gender and social position. This research also demonstrates how investigations of adolescence can permit a more holistic interpretation of this transitional period of the life course and exposes the transitional experiences of these individuals as they come of age in the Roman Empire. / Dissertation / Candidate in Philosophy / There are kids, and there are adults, but what about those in-between? When does one become the other? These are the questions driving this doctoral research, and in applying them to the Roman Empire, I examine patterns of puberty and changes in diet, to better understand when children started to look like and eat like adults in their communities. This research demonstrates that adulescentia (i.e., adolescence) was a period of extended biological development, with puberty occurring between 9 and 20 years of age. Changes in diet, however, occurred in different ways for males and females, and across space and time within the Roman Empire, suggesting that there was not a singular experience or definition of adulescentia, but that lived experiences were more variable and nuanced than ancient literary sources suggest.

No description available.

<p>By studying the boron isotope composition of marine carbonates, the effectiveness of the tracer to reconstruct the ancient seawater pH and, in turn, atmospheric pCO₂ can be assessed. The boron isotope-pH proxy relies on the hypothesis that only B(OH)₄^-, which has a known boron isotope composition with respect to pH, is incorporated into the carbonate crystal lattice. This research synthesized inorganic aragonite from a range of stable pH values to quantify the dependence of aragonite <em>δ</em>¹¹B on the pH of the precipitating solution. The increasing boron isotope composition of aragonite with increasing pH is consistent with sole incorporation of B(OH)₄^- into the carbonate. The sensitivity of the acid dissociation and isotope equilibrium constants make it difficult to confirm whether or not B(OH)₄^- is the only species contributing to the boron isotope composition of aragonite. The relationship between the boron isotope composition of marine carbonates and ocean pH has wide appeal and, if properly understood, could provide tremendous insight into the history of Earth’s climate.</p> <p>This research also evaluated carbon isotope fractionation between aragonite and dissolved inorganic carbon (DIC) in high ionic strength systems at 25 °C and found it to be consistent with carbon isotope fractionation in low ionic strength environments. The analysis of various isotopic compositions within this study led to the development of new methodology to simultaneously measure the oxygen isotopes of water and carbon isotopes of DIC from small solution samples using continuous flow isotope ratio mass spectrometry (CF-IRMS).</p> / Master of Science (MSc)

The purpose of this study was to apply oxygen and carbon stable isotope microsampling techniques to the seasonal banding of the otoliths of the Atlantic cod, Gadus morhu~ in order to determine their potential use in reconstructing the environmental conditions experienced by cod. A reconstruction of the changes in environmental temperature is seen as particularly applicable to the determination of cod migration routes based on the known temperature profile of the North Atlantic. Transverse thin sections of six otoliths from cod taken off the coast of Atlantic Canada were prepared using standard methods. Material was sampled from each semiannual band of the otoliths and run on a Finnigan MAT 251 ratio mass spectrometer to determine 0180 and 013C. The results for 0180 indicated that the otoliths had an approximate initial value of either 1.4%o or l.O%o for sample material taken from the nucleus. The 0180 signal was characterized by oscillating values in which sample material from hyaline bands corresponded predominantly with the troughs and sample material from the opaque bands corresponded with the peaks. The average range of 0180 was found to be 0.87%o corresponding to a temperature range of 3.6°C which was within the expected 3 to 4 °C seasonal average temperature shift experienced by cod. Seasonal cycling was apparent in three of the otoliths, with semi-annual values alternating between high opaque bands and low hyaline bands. It was concluded that seasonal temperature changes due to migration from offshore to inshore waters are recorded in the 0180 signal and that future sampling should attempt to resolve several samples within each seasonal band in order to resolve the migratory changes in temperature on an sub-annual basis. It is also suggested that experiments be carried out to determine the species specific 0180 versus temperature relationship for cod to make accurate interpretation of the data possible. The o13C signal was found to be characterized by an increasing logarithmic trend in o13C. The 013C signal was observed to increase over the first three years of growth and to level off at age 4 and fluctuate at a value close to O%o. The otoliths of cod were found to contain a high proportion of inorganic carbon with a minimum 013C value of -4.53%o and a maximum of 0.23%o. It was suggested that the initial increase in 013C was a product of a combination of factors affecting metabolic rate and therefore, indirectly, the amount of metabolically derived carbon circulating in the blood. It was concluded that further research into the growth and development of cod was necessary in order to reach a comprehensive understanding of the biological processes responsible for the observed trends in 013C. 0180 was plotted against 013C for samples from growth bands of age four or greater and found to have a positive correlation with a slope of 0.269 (S.E. 0.049) and an r-squared of 0.537, P < 0.0001 when the results for otolith 176 were excluded due an anomalous trend in that data set. Two hypotheses were suggested to account for the observed positive correlation, a metabolic/temperature effect, and a depth/temperature effect. It was concluded that, with further research into the controlling factors behind the fluctuations in 013C, the 013C signal may provide a second source of information with regards to changes in habitat and environmental characteristics over the life time of the cod. It is suggested that a study be carried out to determine the amount of metabolic carbon incorporated into the otolith in order to clarify the observed trends. / Thesis / Candidate in Philosophy

Determining the AA availability and metabolism in ruminant is a big challenge due to the rumen fermentation and complicated post absorption utilization. Current techniques used for direct determination of AA absorption and metabolism are laborious and expensive with large variation. The objectives of this project were to investigate AA availability of rumen undegradable protein, develop a stable isotope technique for determination of microbial protein and to evaluate the metabolism of amino acids in mammary glands of dairy cattle using stable isotope-based approaches. In the first experiment, seven heifers (258 ± 28 kg BW) were randomly chosen and assigned to 8 treatment sequences in a 7 x 8, incomplete, Latin square design. Treatments were a basal diet (BD), and 10% (DM basis) of BD replaced by corn silage (CS), grass hay (GH), alfalfa hay (AH), dried distillers grain (DDGS), soybean hulls (SH), wet brewers grain (BG), or corn grain (CG). Individual essential AA availabilities for corn silage, grass hay, alfalfa hay, dried distillers grain, soyhulls, brewers grain and corn grain were 33.4, 29.9, 34.1, 40.6, 28.8, 41.2, and 36.5% of the essential AA in each of the respective ingredients when a loss of 8.27% to splanchnic utilization during first pass was assumed; however, availability varied across individual essential AA. In the second experiment, twelve cows were blocked into 3 groups according to days in milk and randomly assigned to 4 treatments in a repeated 4 x 4 Latin square design with 2 factors to evaluate the essential AA availability from microbial protein and rumen undegradable protein under different rumen fermentation conditions. The 4 treatments were high rumen undegradable protein and high starch (HPHS), low rumen undegradable protein and high starch (LPHS), high rumen undegradable protein and low starch (HPLS) and low rumen undegradable protein and low starch (LPLS). Microbial protein synthesis calculated from purine derivatives was positively associated with rumen degradable protein, which was consistent with total microbial AA entry derived from the isotope dilution model indicating that the isotope based approach was representative. The individual essential AA availability from microbial protein was determined by isotope technique, whereas the PD method was just total PD absorption reflecting CP absorption. The metabolizable AA estimates from NDS nutritional model was similar to results from isotope dilution models, but with smaller difference among treatments. The microbial protein estimated from White's model showed the same trend among treatments compared to isotope dilution model, which may imply it represents the rumen fermentation better. The average essential AA digestibility for microbial AA was 82%, which varied across individual AA and treatments. In the third experiment, four cows (78 ± 10 DIM) were used to study the effects of jugular infusion of 2 groups of AA on essential AA uptake and metabolism by mammary glands in a 4 x 4 Latin square design. Treatments were jugular infusion of saline (CON), methionine plus lysine plus histidine (MKH), isoleucine plus leucine (IL), or MKH plus IL (MKH+IL). The MKH increased milk protein yield in high producing dairy cows. The IL infusion increased milk and milk lactose yields. The production response was associated with a change in mammary plasma flow together with changes in AA uptake and metabolism in mammary gland. Mammary uptake of essential AA was 135 % of milk protein output. Efflux of EAA from the mammary to blood was 13-61% of influx, which was high for BCAA but low for Met and Lys. Changes in influx and efflux resulted in net uptake difference of infused essential AA that were responsive to varying supplies resulting in maintenance of homeostasis. The proportion of AA catabolized and used for milk protein was affected by EAA infusion, which demonstrated plasticity of mammary gland in AA metabolism. Overall, results suggested essential AA availability from rumen undegraded protein and microbial protein varied across individual AA and diets and can be affected by rumen fermentation. After absorption, EAA transport into mammary tissue was bi-directional and their metabolism was affected by AA supply and energy. Using a single coefficient to represent all AA digestibility in MCP or feed ingredient and an integrated efficiency of MP-AA converted into milk protein is inaccurate. / Doctor of Philosophy / Studies in monogastric animals have showed that balancing AA supply with animal requirements can improve the efficiency of N utilization. In order to build a model for AA balanced diet formulation, the composition of feed ingredients, the profile and digestibility of EAA for the rumen undegradable protein and microbial protein, the partition and efficiency of EAA utilization in mammary glands must be determined accurately. However, current AA degradation, digestibility and metabolism data used in nutritional models are from in vitro and in situ studies, which have not been fully validated against in vivo observations. This research used an in vivo stable isotope-based approach to determine amino acid availability for commonly used feed ingredients in dairy industry. The microbial protein AA and rumen undegradable protein AA availability was determined by adapting this isotope technique and introducing another isotope into rumen to label microbes. In addition, by coupling stable isotope tracers with arterio-venous difference technique and compartmental modelling, essential AA metabolism in mammary glands of dairy cows were qualified. Total essential AA availabilities for corn silage, grass hay, alfalfa hay, dried distillers grain, soyhulls, brewers grain and corn grain were similar to values from meta-analysis of mobile bag results, but the availabilities of individual AA were more variable compared to in vitro and in situ results. The model derived microbial AA availability was consistent with the microbial protein calculated from NDS and Felming's model. However, our model predicted a lower proportion of metabolizable AA from microbial protein under diets including low rumen degradable protein, which might imply the NDS nutritional model overestimates microbial protein under low protein diets. The microbial protein estimated from White's model showed the same trend among treatments compared to isotope dilution model, which may imply it represents the rumen fermentation better. The averaged essential AA digestibility form microbial protein was 82%, which varied across individual AA and treatments. After absorption, mammary uptake of essential AA was 135 % of milk protein output. Cellular efflux represented 13 to 61% of essential AA uptake. The proportion of AA catabolized and used for milk protein was affected by essential AA infusion, which demonstrated the plasticity of mammary glands in AA metabolism. In conclusion, the results from isotope technique quantified the essential AA availability from rumen undegradable protein for various feed ingredients and from microbial protein under different feeding conditions. The essential AA transport and metabolism in mammary glands were regulated by multi factors and essential AA supply.

A numerical model which determines the geometry of a threshold channel was recently developed. Such a model is an important tool for designing unlined irrigation canals and channelization schemes, and is useful when considering flow regulation. However, its applicability is limited in that its continuously curving boundary does not allow for sediment transport, which is an essential feature of natural rivers and streams. That model has thus been modified to predict the shape and stress distribution of an optimal stable channel; a channel with a flat-bed region over which bedload transport occurs, and curving bank regions composed of particles that are all in a state of incipient motion. It is the combination of this channel geometry and the phenomenon of momentum-diffusion, that allows the present model to simulate the "stable bank, mobile bed" condition observed in rivers. The coupled equations of momentum-diffusion and force-balance are solved over the bank region to determine the shape of the channel banks (the bank solution). The width of the channel1s flat-bed region is determined by solving the momentum-diffusion equation over the flat-bed region (the bed solution), using conditions at the junction of the flat-bed and bank regions that ensure matching of the bed and bank solutions. The model was tested against available experimental and field data, and was found to adequately predict the bank shape and significant dimensions of stable channels. To make the model results more amenable to the practic ing engineer, design equations and plots were developed. These can be used as an alternative solution for stable channel design; relieving the practitioner of the need to run the numerical program. The case of a stable channel that transports both bedload and suspended sediment is briefly discussed. Governing equations and a possible solution scheme for this type of channel are suggested; laying the groundwork for the development of an appropriate numerical model. / Ph. D.