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In this work, we have developed an ESIPT-based benzimidazole platform (MO-E1 and MO-E2) for the two-photon cell imaging of ONOO- and a potential ONOO--activated theranostic scaffold (MO-E3). Each benzimidazole platform, MO-E1-3, were shown to rapidly detect ONOO- at micromolar concentrations (LoD = 0.28 μM, 6.53 μM and 0.81 μM respectively). The potential theranostic MO-E3 was shown to release the parent fluorophore and drug indomethacin in the presence of ONOO- but unfortunately did not perform well in vitro due to low solubility. Despite this, the parent scaffold MO-E2 demonstrated its effectiveness as a two-photon imaging tool for the ratiometric detection of endogenous ONOO- in RAW264.7 macrophages and rat hippocampus tissue. These results demonstrate the utility of this ESIPT benzimidazole-based platform for theranostic development and bioimaging applications.

In recent years, it has become evident that limitations exist in our ability to meaningfully assess palaeodiet using stable isotope compositions. These limitations in part arise because many of the fundamental assumptions about tissue-diet relationships are poorly understood. In order to redress this deficiency, a controlled feeding experiment was undertaken to define the impact of terrestrial- vs. marine-derived dietary protein consumption on consumer tissue carbon isotopic compositions (δ13C). Two generations of pigs were raised on one of five feeds with varying proportions of terrestrial (soy) and marine (fish meal) protein. A comprehensive range of tissues and fluids from 49 pigs was submitted for δ13C analysis. The observed tissue–whole diet and tissue–dietary protein carbon isotopic offsets were found to be highly dependent on the percentage of marine protein in diet. We suggest that the trend in δ13C offsets most likely derives from the increased routing of non-essential amino acids, especially glycine, with the increasing proportion of marine protein in the diet. These findings demonstrate that solely using bulk δ13C compositions not only masks considerable information about diet, but may also lead to erroneous representations of marine and terrestrial resource consumption in the past.

Sulphur-isotope determinations are becoming increasingly useful for palaeodietary reconstruction, but knowledge of isotopic discrimination between diet and various tissues remains inadequate. In this study, we explore the sensitivity of δ34Stissue values to changes in δ34Sdiet values, sulphur isotopic discrimination between diet and consumer, and the potential impact of terrestrial vs. marine protein consumption on these discrimination offsets. We present new δ34S values of bone collagen, muscle, liver, hair, milk and faeces from ten mature sows, ten piglets and fifteen adolescent pigs from a controlled feeding study. The δ34Stissue values were found to co-vary with the δ34Sdiet values, the δ34Stissue – δ34Sdiet isotopic offsets (Δ34Stissue-diet) are small but consistent, and dietary protein source does not systematically alter the Δ34Stissue-diet isotopic discrimination. The outcomes of this study are of particular relevance to questions that are difficult to resolve using carbon and nitrogen stable isotopes alone, and will also be useful in regions where terrestrial, freshwater, and marine resources could have all potentially contributed to human diet.

Compound-specific amino acid carbon-isotope compositions have shown particular promise for elucidating dietary behaviors in complex environmental contexts, and may also be able to mitigate the effect of many of the limitations inherent to palaeodietary reconstructions. Here, we investigate the efficacy of compound-specific amino acid isotopic proxies in characterizing the consumption of different dietary protein sources using amino acid carbon-isotope compositions for humans and fauna from Rössberga (Early to Middle Neolithic), Köpingsvik (Mesolithic and Middle Neolithic), and Visby (Medieval Period), Sweden. We also assess the explanatory capabilities of an isotopic mixing model when used with essential amino acid carbon-isotope compositions of humans and local fauna. All three isotopic proxies distinguished among humans from the three sites consistently and informatively, and were able to enhance the broad interpretations made using bulk isotopic compositions. The mixing model palaeodietary reconstruction revealed considerable diversity in relative protein source contributions among individuals at both Köpingsvik and Visby. Comparing the mixing model for bulk carbon- and nitrogen-isotope compositions to the model for essential amino acid isotopic compositions further demonstrated the likelihood of underestimation and overestimation of marine protein consumption for both aquatic-dominant and mixed marine-terrestrial diets when using bulk isotopic compositions.

In this study, femoral collagen, rib collagen, femoral muscle, loin muscle and liver samples from sows, piglets and pigs raised in a controlled feeding study are analysed for their nitrogen-isotope compositions. The objectives of this research are to investigate the relationship between tissue and dietary δ15N values across age categories under controlled feeding and housing conditions, and to assess tissue 15N-enrichment relative to diet when pigs of different ages are consuming terrestrial, marine, or mixed terrestrial-marine dietary protein. There is a strong linear relationship between all tissue δ15N values and the amount of marine protein consumed, but the δ15N values do not become consistently elevated for all individuals consuming the same diet until at least 25% of the dietary protein source is marine-derived. Adolescent pigs also had consistently lower δ15N values than either piglets or sows consuming the same diet for collagen and muscle, which is most likely caused by the differences in growth rate among the age categories. Further, for some tissues and animals, a linear relationship between the amount of marine protein consumed and the Δ15NTissue – Whole Diet offset was also observed. We suggest that this variability results from both age-associated growth rates and differential incorporation of amino acids from terrestrial and marine dietary protein into rapidly growing tissue.

Of central importance to palaeodietary reconstruction is a clear understanding of relative contributions of different terrestrial (i.e., C3 vs. C4 plants) and aquatic (i.e., freshwater vs. marine) resources to human diet. There are, however, significant limitations associated with the ability to reconstruct palaeodiet using bulk collagen stable isotope compositions in regions where diverse dietary resources are available. Recent research has determined that carbon-isotope analysis of individual amino acids has considerable potential to elucidate dietary protein source where bulk isotopic compositions cannot. Using δ13CAA values for human and faunal remains from Zvejnieki, Latvia (8th – 3rd millennia BCE), we test several isotopic proxies focused on distinguishing freshwater protein consumption from both plant-derived and marine protein consumption. We determined that the Δ13CGly-Phe and Δ13CVal-Phe proxies can effectively discriminate between terrestrial and aquatic resource consumption, and the relationship between essential δ13CAA values and the Δ13CGly-Phe and Δ13CVal-Phe proxies can differentiate among the four protein consumption groups tested here. Compound-specific amino acid carbon-isotope dietary proxies thus enable an enhanced understanding of diet and resource exploitation in the past, and can elucidate complex dietary behaviour.

Archeological hair from 14 adults from the Nasca Region, Peru (c. AD1-1000) was analyzed for carbon and nitrogen isotopic compositions and cortisol levels. We investigated the relationship between isotopic compositions, which reflect diet, and cortisol, which reflects biogenic cortisol production and chronic stress. Using a case study approach, we determined that there are consistent changes in cortisol production associated with the rapid dietary change characteristic of local mobility. Moreover, changes in nitrogen- and carbon-isotope compositions, when integrated with cortisol levels, enabled inferences to be made about nitrogen metabolism and carbon routing, and elucidated the nature of potential stressors in the months before death. The isotopic and cortisol data suggested a relatively high rate of exposure to stress that is consistent with what is known about the Nasca Region social and physical environments. Of the 14 adults included in this study, six likely suffered from illness/trauma before death, and a further three experienced stress without an observable associated change in isotopic composition. Five individuals also experienced increased stress related to local mobility, inferred from co-occurring changes in cortisol production and dietary shifting. The integration of cortisol and isotopic data revealed individual characteristics of hidden frailty and risk that would not be apparent using more traditional methods of evaluating health status. This approach will provide a powerful enhancement to the understanding of stress, morbidity, and well-being developed through skeletal analysis.

In archaeological research, human bone and enamel bioapatite isotopic compositions are commonly used to reconstruct residential and dietary histories. In doing so, enamel and bone bioapatite are implicitly treated as isotopically equivalent, but recent research has determined that carbonate–carbon and –oxygen isotopic compositions of these two tissues may be offset by several per mil. Here, we compare the isotopic compositions of co-forming bone and enamel from juvenile humans. We also assess the impact of a standard pre-treatment procedure for the removal of organic matter and exogenous carbonates on carbon- and oxygen-isotope compositions and on bioapatite crystallinity and carbonate content. Pre-treatment procedures had minimal effect on both enamel and bone carbon and oxygen isotopic compositions (±0.4–±0.9‰) and bioapatite crystallinity, and effectively removed exogenous carbonates. The offset between enamel and bone phosphate–oxygen isotopic compositions is relatively small (±0.7 ± 0.5‰). The offsets for carbonate–oxygen (+1.4 ± 1.0‰) and –carbon (+4.3 ± 1.2‰) are larger, and enamel is consistently 18 O- and 13 C-enriched relative to bone. Interpreted conservatively, phosphate–oxygen isotopic data from paired enamel and bone remain suitable for determining residential history, whereas the isotopic compositions of carbonate–oxygen and –carbon from enamel and bone bioapatite are inherently different and cannot be compared uncritically.

While the use of radiogenic strontium isotope values to examine paleomobility is increasingly common in the Andes, and beyond, many questions about baseline variability remain. To better understand baseline radiogenic strontium isotope compositions in the Andes, we present new 87Sr/86Sr values from Peruvian soil samples. Modern soil samples were collected from agricultural fields from the following areas in central and southern Peru: Arequipa, Atico, Camana, Chala, Cusco, Ica, Ilo, Lima, Mejia, Moquegua, Nazca, Ocona, Palpa, Pisco, Puno, Tacna, and Yauca. Samples were partially dissolved to better approximate the bioavailable strontium. Radiogenic strontium isotope values from the partially dissolved soil samples range from 87Sr/86Sr = 0.70202 to 0.71894 and, for all soil samples, have a mean of 87Sr/86Sr = 0.70773 ± 0.00166 (1σ, n = 114). In general, the 87Sr/86Sr values measured for soil samples collected from modern agricultural fields reflect the expected 87Sr/86Sr values based on bedrock geology. Comparing our new soil data with published radiogenic strontium isotope data for bedrock, soil, water, and faunal samples provides constraints on the regions in the Andes that can, and cannot, be distinguished through radiogenic strontium isotope analysis.

The topography of the Andean Region results in short travelling distances among ecologically distinct production zones. As such, it is possible to infer relative changes in residence based on the spatial variability in the isotopic composition of food resources. Here, we determine long-term diet through carbon- and nitrogen-isotope analysis of bone collagen for twenty-nine individuals from Cahuachi, an important ceremonial centre in the Nasca Region. We also reconstruct the temporal sequence of change in dietary isotopic compositions along hair samples for seventeen individuals buried at Cahuachi and the neighbouring site of Huaca del Loro. The collagen isotopic data for individuals buried at Cahuachi indicate that the average diet was a mix of C3 and C4 plant foods with greater reliance on maize, and included the variable consumption of plant-derived protein and terrestrial animals. Sequential isotopic analyses of hair reveal distinctive patterns of dietary shifting that distinguish seasonally changing diets from access to multiple production zones. We argue that short-term dietary heterogeneity in this context can be interpreted to represent flexibility as a risk-minimising strategy through the interaction between food acquisition and participation in local mobility among the Nasca.

In this study, we used oxygen- and hydrogen-isotope data from human bone (δ18O) and modern environmental water samples (δ18O and δD) to investigate geographic origins of individuals buried at Cahuachi, a ceremonial centre in the Nasca region of Peru (c.AD1-1000). Our objective was to characterise the natural variation in water stable isotopic composition in the Rio Grande de Nasca drainage, and then to use these data to better infer place of origin for 30 adults interred at Cahuachi. Using the δ18O and δD values of 63 modern environmental water samples, it was possible to differentiate among the northern and southern river middle valleys, and to infer the isotopic composition of drinking water at higher elevations. Over half of the individuals included in this study had drinking water oxygen-isotope compositions consistent with places of origin away from Cahuachi during the last 10 to 25 years of life, perhaps in the northern river middle valleys or in the upper valleys/sierra. The environmental water stable isotopic baseline developed in this study enabled a better understanding of the natural variation of waters in the Rio Grande de Nasca drainage. As a result, it was possible to assess the geographic range of place of origin for these individuals with greater certainty. Taken together, these data support the idea of Cahuachi as a place of both local and regional significance, with individuals from distant parts of the Rio Grande de Nasca drainage travelling to and/or transporting the dead to the site for death or burial. Copyright © 2011 John Wiley & Sons, Ltd.

As a product of physiological status and the social and physical environments, stress has significant impact on health and well-being in both ancient and contemporary societies. In bioarchaeological research, stress is characterized using an array of skeletal indicators that record stressful periods during childhood and adulthood. In modern clinical research, exposure to stress can be assessed using systemic cortisol levels that have been shown to fluctuate in response to experienced stress. Analysis of cortisol levels in archaeological hair should enable assessment of stress during a short, but critical, period of an individual's life. For this pilot study, we selected hair samples from ten individuals from five different archaeological sites in Peru, and analyzed them in segments to determine cortisol levels. These data demonstrate that it is possible to observe biogenic patterns of cortisol production, and that individual experiences of stress can be reconstructed for the period of time represented by each hair sample. Analysis of cortisol levels in hair has the potential to be a valuable short-term dynamic stress indicator that will complement paleopathological and biochemical studies of health and stress, and permit the reconstruction of increasingly detailed life histories.

Understanding childhood experiences of health and well-being is essential to reconstructing ancient life-ways. Here, archaeological hair samples from five juveniles from Cahuachi and near Huaca del Loro in the Nasca Region, Peru, are analyzed for their carbon- and nitrogen-isotope compositions and cortisol levels. Stable isotopic data are used to investigate dietary change and nitrogen metabolism, and cortisol levels are used to infer exposure to stress. Using a case study approach, we determined that juveniles have distinct, individualized experiences of diet and morbidity, which are, in some cases, similar to adult experiences in the same region. Overall, Nasca Region juveniles have high systemic cortisol levels (1444 ± 402 ng/g) compared to Peruvian adults (281 ± 35 ng/g; Webb et al., 2010 ). Younger juveniles have comparatively high δ15N values that decrease over several months, suggesting transition from breast milk to a weaning diet. Older juveniles exhibit patterns of dietary shifting similar to those determined for adults in the region, or suggestive of particular socioeconomic roles. This study demonstrates the value of applying biomolecular methods to juvenile mummified remains to better understand the life histories of children in archaeological contexts.