Hairs in old books isotopically reconstruct the eating habits of early modern Japan.
ABSTRACT: To complement literature-based historical knowledge of the eating habits of 17th- and 18th-century Japan, we analysed carbon and nitrogen isotope ratios (?13C and ?15N, respectively) of human hairs embedded in cover paper of Japanese books printed during 1690s-1890s, taking regional and temporal variations into consideration. We purchased 24 book sets from second-hand book markets. Twenty-three sets contained enough human hairs, which were non-destructively extracted from the thick, recycled paper of the book covers and used to measure the ?13C and ?15N values, found to be identical within each book set. Relatively low ?13C values and high ?15N values suggested that people depended on rice, C3 vegetables, and fish, more exclusively than contemporary Japanese people. The relatively high ?13C values found in Edo (Tokyo) might be associated with the preference for C4 millets by Edo people as a measure against beriberi (locally recognised as the Edo affliction). The ?15N values gradually increased over 200 years, indicating an increase in the contribution of marine fish both as food and fertiliser for rice fields as suggested by literature-based studies. Further collection of hairs from books will enable a thorough examination of regional and temporal variations to better understand the pre-globalised food culture.
Project description:Nitrogen and carbon stable isotopic compositions (?15N and ?13C) of consumers have been used for physiological and food web studies. Previous studies have shown ?15N and ?13C values are affected by several biological and environmental factors during starvation, but the generality of the effect of starvation on ?15N and ?13C values has not yet been tested. Here, we performed a meta-analysis to evaluate the effects of starvation on ?15N and ?13C values of consumers, and the underlying factors that may explain the observed variation. The ?15N and ?13C values were calculated as the differences between the final ?15N and ?13C values of consumers (post-starvation) and the pre-starvation values on each experiment. Our meta-analysis showed a large variation in the ?15N and ?13C values of consumers (?15N range: -0.82 to 4.30‰; mean: 0.47‰ and ?13C range: -1.92 to 2.62‰; mean: 0.01‰). The ?15N values of most consumers increased along the length of the starvation period and were influenced by nitrogen excretion and thermoregulation types, probably because differences in nitrogen metabolism and thermoregulation affect nitrogen processing and excretion rates. None of our predictor variables accounted for the variation in ?13C values, which showed both increases and decreases due to fasting. Our findings suggest that starvation results in changes in consumer ?15N values which are mainly explained by the length of the fasting period and by nitrogen and energy metabolism, but the underlying mechanisms of the starvation effects on ?13C values seem to be more complex than previously thought.
Project description:The elemental (C/N) and stable isotopic (?13C, ?15N) compositions and compound-specific ?15N values of amino acids (?15NAA) were evaluated for coral holobionts as diagnostic tools to detect spatiotemporal environmental heterogeneity and its effects on coral health. Hermatypic coral samples of eight species were collected at 12 reef sites with differing levels of pollution stress. The C/N ratios, ?13C values, and ?15N values of coral tissues and endosymbiotic algae were determined for 193 coral holobionts, and the amino acid composition and ?15NAA values of selected samples were analyzed. ?15N values were influenced most by pollution stress, while C/N ratios and ?13C values depended most strongly on species. The results imply that ?13C and ?15N values are useful indicators for distinguishing the ecological niches of sympatric coral species based on microhabitat preference and resource selectivity. Using ?15NAA values, the trophic level (TL) of the examined coral samples was estimated to be 0.71 to 1.53, i.e., purely autotrophic to partially heterotrophic. Significant portions of the variation in bulk ?15N and ?13C values could be explained by the influence of heterotrophy. The TL of symbionts covaried with that of their hosts, implying that amino acids acquired through host heterotrophy are translocated to symbionts. Dependence on heterotrophy was stronger at polluted sites, indicating that the ecological role of corals changes in response to eutrophication.
Project description:The measurement of bulk tissue nitrogen (?15N) and carbon isotope values (?13C) chronologically along biologically inert tissues sampled from offspring can provide a longitudinal record of their mothers' foraging habits. This study tested the important assumption that mother-offspring stable isotope values are positively and linearly correlated. In addition, any change in the mother-offspring bulk tissues and individual amino acids that occurred during gestation was investigated. Whiskers sampled from southern elephant seal pups (Mirounga leonina) and temporally overlapping whiskers from their mothers were analyzed. This included n?=?1895 chronologically subsampled whisker segments for bulk tissue ?15N and ?13C in total and n?=?20 whisker segments for amino acid ?15N values, sampled from recently weaned pups (n?=?17), juvenile southern elephant seals (SES)?<?2 years old (n?=?23) and adult female SES (n?=?17), which included nine mother-offspring pairs. In contrast to previous studies, the mother-offspring pairs were not in isotopic equilibrium or linearly correlated during gestation: the ?15N and ?13C mother-offspring offsets increased by 0.8 and 1.2‰, respectively, during gestation. The foetal bulk ?15N values were 1.7?±?0.5‰ (0.9-2.7‰) higher than mothers' ?15N values before birth, while the foetal ?13C increased by ~1.7‰ during gestation and were 1.0?±?0.5‰ (0.0-1.9‰) higher than their mothers' ?13C at the end of pregnancy. The mother-offspring serine and glycine ?15N differed by ~4.3‰, while the foetal alanine ?15N values were 1.4‰ lower than that of their mothers during the third trimester of pregnancy. The observed mother-offspring ?15N differences are likely explained by shuttling of glutamate-glutamine and glycine-serine amongst skeletal muscle, liver, placenta and foetal tissue. Foetal development relies primarily on remobilized endogenous maternal proteinaceous sources. Researchers should consider foetal physiology when using offspring bulk tissue isotope values as biomarkers for the mother's isotopic composition as part of monitoring programmes.
Project description:Roughly eight million people live on Long Island, including Brooklyn and Queens, and despite improvements in wastewater treatment, nearly all its coastal waterbodies are impaired by excessive nitrogen. We used nutrient stoichiometry and stable isotope ratios in estuarine biota and soils to identify water pollution hot spots and compare among potential indicators. We found strong gradients in ?15N values, which were correlated with watershed land cover, population density, and wastewater discharges. Weaker correlations were found for ?13C values and nutrient stoichiometric ratios. Structural equation modeling identified contrasts between western Long Island, where ?15N values depended on watershed population density, and eastern Long Island where ?15N values reflected agriculture and sewage discharges. These results illustrate the use of stable isotopes as water quality indicators, and establish a baseline against which the efficacy of strategies to reduce nutrients can be measured.
Project description:Scat is frequently used to study animal diets because it is easy to find and collect, but one concern is that gross fecal analysis (GFA) techniques exaggerate the importance of small-bodied prey to mammalian mesopredator diets. To capitalize on the benefits of scat, we suggest the analysis of scat carbon and nitrogen isotope values (?13C and ?15N). This technique offers researchers a non-invasive method to gather short-term dietary information. We conducted three interrelated studies to validate the use of isotopic values from coyote scat: 1) we determined tissue-to-tissue apparent C and N isotope enrichment factors (?13* and ?15*) for coyotes from road kill animals (n = 4); 2) we derived diet-to-scat isotope discrimination factors for coyotes; and 3) we used field collected coyote scats (n = 12) to compare estimates of coyote dietary proportions from stable isotope mixing models with estimates from two GFA techniques. Scat consistently had the lowest ?13C and ?15N values among the tissues sampled. We derived a diet-to-scat ?13C value of -1.5‰ ± 1.6‰ and ?15N value of 2.3‰ ± 1.3‰ for coyotes. Coyote scat ?13C and ?15N values adjusted for discrimination consistently plot within the isotopic mixing space created by known dietary items. In comparison with GFA results, we found that mixing model estimates of coyote dietary proportions de-emphasize the importance of small-bodied prey. Coyote scat ?13C and ?15N values therefore offer a relatively quick and non-invasive way to gain accurate dietary information.
Project description:There is limited information that provides a comprehensive understanding of the trophic ecology of Mexican Pacific harbor seal (Phoca vitulina richardii) colonies. While scat analysis has been used to determine the diet of some colonies, the integrative characterization of its feeding habits on broader temporal and spatial scales remains limited. We examined potential feeding grounds, trophic niche width, and overlap, and inferred the degree of dietary specialization using stable carbon and nitrogen isotope ratios (?13C and ?15N) in this subspecies. We analyzed ?13C and ?15N on fur samples from pups collected at five sites along the western coast of the Baja California Peninsula, Mexico. Fur of natal coat of Pacific harbor seal pups begins to grow during the seventh month in utero until the last stage of gestation. Therefore pup fur is a good proxy for the mother's feeding habits in winter (~December to March), based on the timing of gestation for the subspecies in this region. Our results indicated that the ?13C and ?15N values differed significantly among sampling sites, with the highest mean ?15N value occurring at the southernmost site, reflecting a well-characterized north to south latitudinal 15N-enrichment in the food web. The tendency identified in ?13C values, in which the northern colonies showed the most enriched values, suggests nearshore and benthic-demersal feeding habits. A low variance in ?13C and ?15N values for each colony (<1‰) and relatively small standard ellipse areas suggest a specialized foraging behavior in adult female Pacific harbor seals in Mexican waters.
Project description:OBJECTIVES: The purpose of the Health Sciences Library System (HSLS) electronic book (e-book) study was to assess use, and factors affecting use, of e-books by all patron groups of an academic health sciences library serving both university and health system-affiliated patrons. METHODS: A web-based survey was distributed to a random sample (n=5,292) of holders of library remote access passwords. A total of 871 completed and 108 partially completed surveys were received, for an approximate response rate of 16.5%-18.5%, with all user groups represented. Descriptive and chi-square analysis was done using SPSS 17. RESULTS: Library e-books were used by 55.4% of respondents. Use by role varied: 21.3% of faculty reported having assigned all or part of an e-book for class readings, while 86% of interns, residents, and fellows reported using an e-book to support clinical care. Respondents preferred print for textbooks and manuals and electronic format for research protocols, pharmaceutical, and reference books, but indicated high flexibility about format choice. They rated printing and saving e-book content as more important than annotation, highlighting, and bookmarking features. CONCLUSIONS: Respondents' willingness to use alternate formats, if convenient, suggests that libraries can selectively reduce title duplication between print and e-books and still support library user information needs, especially if publishers provide features that users want. Marketing and user education may increase use of e-book collections.
Project description:Natural abundances of stable nitrogen and carbon isotopes (?15N and ?13C) can vary with both dietary intake and metabolic (specifically catabolic) state. In low-income countries, weaning is a period of dietary transition from milk to plant-based foods and a high-risk period for malnutrition. We explored how diet and malnutrition impact hair ?15N and ?13C in young children by an observational, cross-sectional study in Cox's Bazar District, Bangladesh [255 children, 6-59 months with 19.6% wasted (7.1% severely) and 36% stunted (9.8% severely)]. Hair ?15N and ?13C exhibited exponential decreases with age, with the loss of one trophic level (3.3‰ and 0.8‰, respectively) from 6 to 48 months, which we associate with the shift from exclusive breastfeeding to complete weaning. After adjustment for age and breastfeeding status, hair isotopic values were unaffected by wasting but lower in severe stunting (-0.45‰ to -0.6‰, P?<?0.01). In this population of young children, whose isotopic values in hair primarily depended on age, we failed to observe any effect of wasting, likely due to opposite, compensating effects between dietary and metabolic changes involved. In contrast, we evidenced low ?15N and ?13C values in severely stunted children that likely indicate chronic exposure to diets low in animal products.
Project description:Stable isotope analysis (SIA) is an important tool for investigation of animal dietary habits for determination of feeding niche. Ideally, fresh samples should be used for isotopic analysis, but logistics frequently demands preservation of organisms for analysis at a later time. The goal of this study was to establish the best methodology for preserving forest litter-dwelling crickets for later SIA analysis without altering results. We collected two cricket species, Phoremia sp. and Mellopsis doucasae, from which we prepared 70 samples per species, divided among seven treatments: (i) freshly processed (control); preserved in fuel ethanol for (ii) 15 and (iii) 60 days; preserved in commercial ethanol for (iv) 15 and (v) 60 days; fresh material frozen for (vi) 15 and (vii) 60 days. After oven drying, samples were analyzed for ?15N, ?13C values, N(%), C(%) and C/N atomic values using continuous flow isotope ratio mass spectrometry. All preservation methods tested, significantly impacted ?13C and ?15N and C/N atomic values. Chemical preservatives caused ?13C enrichment as great as 1.5‰, and ?15N enrichment as great as 0.9‰; the one exception was M. doucasae stored in ethanol for 15 days, which had ?15N depletion up to 1.8‰. Freezing depleted ?13C and ?15N by up to 0.7 and 2.2‰, respectively. C/N atomic values decreased when stored in ethanol, and increased when frozen for 60 days for both cricket species. Our results indicate that all preservation methods tested in this study altered at least one of the tested isotope values when compared to fresh material (controls). We conclude that only freshly processed material provides adequate SIA results for litter-dwelling crickets.
Project description:Competition for resources within a population can lead to niche partitioning between sexes, throughout ontogeny and among individuals, allowing con-specifics to co-exist. We aimed to quantify such partitioning in Antarctic fur seals, Arctocephalus gazella, breeding at South Georgia, which hosts ~95% of the world's population. Whiskers were collected from 20 adult males and 20 adult females and stable isotope ratios were quantified every 5?mm along the length of each whisker. Nitrogen isotope ratios (?15N) were used as proxies for trophic position and carbon isotope ratios (?13C) indicated foraging habitat. Sexual segregation was evident: ?13C values were significantly lower in males than females, indicating males spent more time foraging south of the Polar Front in maritime Antarctica. In males ?13C values declined with age, suggesting males spent more time foraging south throughout ontogeny. In females ?13C values revealed two main foraging strategies: 70% of females spent most time foraging south of the Polar Front and had similar ?15N values to males, while 30% of females spent most time foraging north of the Polar Front and had significantly higher ?15N values. This niche partitioning may relax competition and ultimately elevate population carrying capacity with implications for ecology, evolution and conservation.