Isotopic analysis of faunal material from South Uist, Western Isles, Scotland

This paper reports on the results from stable isotope analysis of faunal bone collagen from a number of Iron Age and later sites on the island of South Uist, in the Western Isles, Scotland. This preliminary investigation into the isotopic signatures of the fauna is part of a larger project to model the interaction between humans, animals, and the broader environment in the Western Isles. The results demonstrate that the island fauna data fall within the range of expected results for the UK, with the terrestrial herbivorous diets of cattle and sheep confi rmed. The isotopic composition for pigs suggests that some of these animals had an omnivorous diet, whilst a single red deer value might be suggestive of the consumption of marine foods, such as by grazing on seaweed. However, further analysis is needed in order to verify this anomalous isotopic ratio

The Sudbury Neutrino Observatory

The Sudbury Neutrino Observatory is a second generation water Cherenkov detector designed to determine whether the currently observed solar neutrino deficit is a result of neutrino oscillations. The detector is unique in its use of D2O as a detection medium, permitting it to make a solar model-independent test of the neutrino oscillation hypothesis by comparison of the charged- and neutral-current interaction rates. In this paper the physical properties, construction, and preliminary operation of the Sudbury Neutrino Observatory are described. Data and predicted operating parameters are provided whenever possible.Comment: 58 pages, 12 figures, submitted to Nucl. Inst. Meth. Uses elsart and epsf style files. For additional information about SNO see http://www.sno.phy.queensu.ca . This version has some new reference

Untangling the effects of overexploration and overexploitation on organizational performance: The moderating role of environmental dynamism

Because a firm's optimal knowledge search behavior is determined by unique firm and industry conditions, organizational performance should be contingent oil the degree to which a firm's actual level of knowledge search deviates from the optimal level. It is thus hypothesized that deviation from the optimal search, in the form of either overexploitation or overexploration, is detrimental to organizational performance. Furthermore, the negative effect of search deviation oil organizational performance varies with environmental dynamism: that is, overexploitation is expected to become more harmful. whereas overexploration becomes less so with all increase in environmental dynamism. The empirical analyses yield results consistent with these arguments. Implications for research and practice are correspondingly discussed

Assessing natural variation and the effects of charring, burial and pre-treatment on the stable carbon and nitrogen isotope values of archaeobotanical cereals and pulses

The aim of this study is to assess the potential of charred archaeobotanical cereal grain and pulse seed δ13C and δ15N values to provide evidence of crop growing conditions and as a potential component of palaeodietary studies. In order to reliably interpret archaeobotanical δ13C and δ15N values it is necessary to take into account the impact of charring, burial and laboratory pre-treatment procedures. We examine the effects of charring and burial on bulk δ13C, δ15N, %C, %N and C:N ratios in modern cereal and pulse material, and of cleaning by acid–base–acid (ABA) pre-treatment on modern and archaeobotanical charred material. Our study utilised bulk grain and seed samples to help account for within-ear/pod and between-plant variability in δ13C and δ15N values. Heating at relatively low temperatures and for prolonged times (230 °C for up to 24 h) is conducive to the formation of well preserved, undistorted charred cereal grain and pulse seed. Heating for 24 h has a systematic and predictable effect on δ15N values, with increases of around 1‰ on average in cereal grains and pulse seeds, and no consistent impact on δ13C values. Increases in δ15N are likely due to the loss of lighter 14N via N-containing volatiles. Burial (for up to 2 years) and ABA pre-treatment have no significant effects on δ13C or δ15N values. After pre-treatment, however, the %C and %N contents of the archaeobotanical material more closely resembles that of the modern charred grains and seeds, suggesting that archaeobotanical remains accumulate non-structural material during burial but retain their original carbon and nitrogen content. Therefore %C, %N contents and C:N ratios can provide useful criteria for assessing archaeobotanical preservation

The effect of charring and burial on the biochemical composition of cereal grains: investigating the integrity of archaeological plant material

Stable isotope analysis of charred archaeobotanical cereal grains has the potential to provide direct evidence of crop growing conditions in the past and to refine palaeodietary predictions. If isotope values of archaeobotanical material are to be considered robust, it is necessary to characterise the compositional changes associated with their charring and burial. This study used a suite of analytical techniques, including FT-IR and solid state 13C NMR, to characterise changes in the biochemical composition of modern einkorn grains with heating at 230 °C for 2 h, 4 h, 8 h and 24 h, encompassing conditions that replicate their undistorted ancient counterparts. The biochemical composition of archaeobotanical charred einkorn grains was also investigated by FT-IR and solid state 13C NMR in order to assess the changes in composition which occur during burial. Results of FT-IR and solid-state 13C NMR show that heating of modern einkorn grains resulted in Maillard reactions between cereal proteins and starch, forming high molecular weight melanoidins, which contain both alkyl and aromatic carbon. Loss of low molecular weight carbon and nitrogen-containing volatiles resulted in a slight but non-systematic increase in the δ13C values and a systematic increase of 0.8‰ in the δ15N values of the charred einkorn grains. Solid-state 13C NMR shows that the ancient charred einkorn grains consisted entirely of aromatic carbon and retained a similar proportion of nitrogen to their modern 24 h charred counterparts, despite a significantly lower concentration of amino acids. This indicates that the amino acid nitrogen in the ancient charred grains was retained in the stable melanoidins whose polymeric structure makes them resistant to subsequent degradation