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Nitrogen Isotope Analyses (nitrogen + isotope_analysis)
Selected AbstractsEffects of lipid extraction on stable carbon and nitrogen isotope analyses of fish tissues: potential consequences for food web studiesECOLOGY OF FRESHWATER FISH, Issue 3 2004M. A. Sotiropoulos Abstract,,, We examined whether solvent-based lipid extractions, commonly used for stable isotope analysis (SIA) of biota, alters ,15N or ,13C values of fish muscle tissue or whole juvenile fish. Lipid extraction from muscle tissue led to only small (<1,) isotope shifts in ,13C and ,15N values. By contrast, ecologically significant shifts (+3.4, for ,13C and +2.8, for ,15N) were observed for whole juvenile fish. Sample variance was not affected by lipid extraction. For tissue-specific SIA, two sample aliquots may be required: a lipid-extracted aliquot for stable carbon isotope analysis when differing lipid content among tissues is a concern, and a nonextracted aliquot for ,15N determination. Whole organism SIA is not recommended because of the mix of tissues having different turnover times; for very small fish, we recommend that fish be eviscerated, decapitated, and skinned to minimise differences with samples of muscle tissue. Resumen 1. Cada vez con mayor frecuencia, los ecólogos de peces utilizan análisis de isótopos estables. Por ello, se hace cada vez más importante comprender las fuentes de variación, - debido a diferencias inherentes entre muestreos biológicos o como resultado de técnicas de procesamiento de muestreo - tanto como identificar estrategias para tratar tales fuentes. Examinamos si la extracción de lípidos basada en disolventes, comúnmente utilizada en análisis de isótopos de carbono estable, altera negativamente los valores de ,15N y ,13C de tejido muscular de tres peces de tamaño pequeño y de peces juveniles completos. 2. La extracción de lípidos de músculo de pez llevó a pequeños cambios isotópicos de + +0.4 a +1.0, y de +0.3 a +0.5, para ,13C y ,15N, respectivamente. Por el contrario, la extracción de lípidos de peces juveniles completos varió marcadamente en +3.4, para ,13C y +2.8, para ,15N - ambos cambios ecológicamente importantes. La varianza de los valores de muestreos de ,13C y de ,15N tanto para tejido muscular como para los peces completos no difirieron entre los muestreos de lípidos extraídos y muestreos sin tratamiento. 3. Nuestros resultados recomiendan el análisis de isótopos estables de tejidos específicos. Cuando ello no es posible o deseable, dos alícuotas de muestreo pueden ser requeridas: una alícuota de lípidos extraídos para el análisis de isótopos de carbono estable cuando la varianza de ,13C, debida a diferencias en el contenido de lípidos de diferentes tejidos, y una alícuota de no-extracción para determinaciones de ,15N. 4. Dada la mezcla de tejidos, el análisis de isótopos de un organismo completo no es recomendable , en el caso de peces muy pequeños, recomendamos que los peces sean eviscerados, decapitados, y despellejados para minimizar las diferencias de muestreos de tejido muscular. [source] A Late Neolithic vertebrate food web based on stable isotope analysesINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 4 2006C. Bösl Abstract Stable carbon and nitrogen isotope analyses of bone collagen, and stable carbon and oxygen isotope analyses of the bone's structural carbonate, were performed on 120 individuals representing 33 vertebrate species, including a single human bone find, collected from the Late Neolithic settlement at Pestenacker, Bavaria, Germany. We were thus capable of reconstructing a rather complex food web and could also address particular issues, such as whether humans influenced the diet of their domestic animals as opposed to their wild relatives, or whether humans perhaps had to compete over food with their domesticates. A rather unexpected result was that freshwater fish, which could be captured in the nearby river Lech, a major tributary of the Danube, contributed to the human diet only occasionally. As for mammals, it was also possible to recognise different trophic levels for birds and aquatic vertebrates, applying stable isotope analyses to both bone collagen and structural carbonate. In the case of fish, ,18O values at least revealed a physiological regularity in terms of temperature preference, besides diet. Conceivably, variability of ,18O in surface water as reflected, for example, by species that avoided human settlements, may help to characterise past ecosystems and to define site catchment exploited by Neolithic man in the course of food acquisition. Copyright © 2006 John Wiley & Sons, Ltd. [source] Isotopic evidence of dietary variations and weaning practices in the Gaya cemetery at Yeanri, Gimhae, South KoreaAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2010Kyungcheol Choy Abstract Stable carbon and nitrogen isotope analyses were conducted to investigate dietary variation in human skeletons (n = 109) from the Gaya cemetery at Yeanri located near Gimhae City, South Korea. The cemetery contained three distinct grave types dating to 4th,7th century AD. The main purposes of this research were to reconstruct palaeodiet in the Gaya population and to explore correlations between stable isotope compositions and burial types, inferred age, and sex of these individuals. The isotopic data indicate that the people at Yeanri consumed a predominantly C3 -based terrestrial diet supplemented with freshwater and/or marine resources. The comparison of isotopic results reveals significant differences in ,13C values among three adult burial types (wood-cist coffin: ,18.5 ± 0.5,, stone-cist coffin: ,18.1 ± 0.6,, mausoleum: ,17.8 ± 0.9,). Males in wood-cist and stone-cist coffins have relatively more elevated mean ,13C and ,15N values than females. The isotopic ratios from the two adult age groups (21,40 years and 40,60 years) indicate that there was no significant dietary change in individuals with age. The isotope data from the infants and children suggest the weaning was a gradual process that was completed between 3 and 4 years of age in the Gaya population. This evidence indicates that the dietary variations within the cemetery reflect social status, sex, and childhood consumption patterns. Am J Phys Anthropol, 2010. © 2009 Wiley-Liss, Inc. [source] The Role of Fruits and Insects in the Nutrition of Frugivorous Bats: Evaluating the Use of Stable Isotope Models,BIOTROPICA, Issue 3 2001L. Gerardo Herrera M. ABSTRACT We estimated the relative contribution of fruits and insects as sources of dietary protein in two species of Neotropical frugivorous bats (Artibeus jamaicensis and Sturnira lilium) using stable carbon and nitrogen isotope analyses. An insectivorous species (Pteronotus parnellii) was also included for comparison. We found constant patterns in stable carbon and nitrogen isotope composition in blood that separated the two species of frugivorous bats from the insectivorous bat. When we used these isotopic values (combined with those of dietary fruits and insects) to estimate the percent contribution of fruits and insects to the diet of the bats, we obtained different results, depending on assumptions and model adopted. We tested models using both 8"N and 8,3C results simultaneously and separately and further used diet-tissue fractionation factors of 3%o for nitrogen and 1 and 3.5%o for carbon. We found that a carbon-based model with a diet-blood enrichment factor of 3.5%o produced the most parsimonious results. The model estimated that A. jamaicensis and S. lilium obtained most of their protein requirements from fruits, whereas P. parnellii fed mostly on insects. No sexual or seasonal variations in the diet of the two frugivorous species were detected. We found no evidence that the diet of sexually active females differed from that of nonsexually active females in the two species of frugivorous bats. We suggest that future studies better define isotopic fractionation between diet and tissues of bats using captive rearing and controlled diets. [source] Diet and mobility in Early Medieval Bavaria: A study of carbon and nitrogen stable isotopesAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2010Susanne Hakenbeck Abstract This study investigates patterns of mobility in Early Medieval Bavaria through a combined study of diet and associated burial practice. Carbon and nitrogen isotope ratios were analyzed in human bone samples from the Late Roman cemetery of Klettham and from the Early Medieval cemeteries of Altenerding and Straubing-Bajuwarenstrasse. For dietary comparison, samples of faunal bone from one Late Roman and three Early Medieval settlement sites were also analyzed. The results indicate that the average diet was in keeping with a landlocked environment and fairly limited availability of freshwater or marine resources. The diet appears not to have changed significantly from the Late Roman to the Early Medieval period. However, in the population of Altenerding, there were significant differences in the diet of men and women, supporting a hypothesis of greater mobility among women. Furthermore, the isotopic evidence from dietary outliers is supported by "foreign" grave goods and practices, such as artificial skull modification. These results reveal the potential of carbon and nitrogen isotope analysis for questions regarding migration and mobility. Am J Phys Anthropol 143:235,249, 2010. © 2010 Wiley-Liss, Inc. [source] Quantitative evaluation of marine protein contribution in ancient diets based on nitrogen isotope ratios of individual amino acids in bone collagen: An investigation at the Kitakogane Jomon siteAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2010Yuichi I. Naito Abstract Nitrogen stable isotopes analysis of individual bone collagen amino acids was applied to archeological samples as a new tool for assessing the composition of ancient human diets and calibrating radiocarbon dates. We used this technique to investigate human and faunal samples from the Kitakogane shell midden in Hokkaido, Japan (5,300,6,000 cal BP). Using compound-specific nitrogen isotope analysis of individual amino acids, we aimed to estimate i) the quantitative contribution of marine and terrestrial protein to the human diet, and ii) the mean trophic level (TL) from which dietary protein was derived from marine ecosystems. Data were interpreted with reference to the amino acid trophic level (TLAA) model, which uses empirical amino acid ,15N from modern marine fauna to construct mathematical equations that predict the trophic position of organisms. The TLAA model produced realistic TL estimates for the Kitakogane marine animals. However, this model was not appropriate for the interpretation of human amino acid ,15N, as dietary protein is derived from both marine and terrestrial environments. Hence, we developed a series of relevant equations that considered the consumption of dietary resources from both ecosystems. Using these equations, the mean percentage of marine protein in the Kitakogane human diet was estimated to be 74%. Although this study is one of the first systematic investigations of amino acid ,15N in archeological bone collagen, we believe that this technique is extremely useful for TL reconstruction, palaeodietary interpretation, and the correction of marine reservoir effects for radiocarbon dating. Am J Phys Anthropol 143:31,40, 2010. © 2010 Wiley-Liss, Inc. [source] Southern French Neolithic populations: Isotopic evidence for regional specificities in environment and dietAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2010Estelle Herrscher Abstract The Middle Neolithic of the Northwestern Mediterranean area (,4500,3500 BC cal) is characterized by the development of food production techniques as well as by increasing social complexity. These characteristics could have had an impact on human dietary patterns. To evaluate human dietary practices and lifeways of the Middle Neolithic populations from the South of France, stable carbon and nitrogen isotope analysis was carried out on 57 human and 53 faunal bones from seven archaeological sites located in the Languedoc and Garonne regions between 20 and 100 km from the Mediterranean Sea, respectively. Results show regional differences in carbon isotope values. Animal and human bones from the Languedoc region are significantly enriched in 13C relative to the Garonne. Conversely, human and dog bones from the Garonne region are significantly enriched in 15N compared to human and dog bones from the Languedoc region. These results highlight the importance of the local ecosystem in human and animal diet as well as a regional differentiation of palaeodietary behavior, which probably relates to economic and social factors. The comparison of stable isotope data with archaeological and biological evidence does not show any significant intra- or interpopulation differences. However, the presence of human outliers suggests that migration probably occurred, perhaps in relation to the trade of animals and/or materials. This study also highlights the importance of investigating local animal stable isotope values for the interpretation of human palaeodiet. Am J Phys Anthropol 2010. © 2009 Wiley-Liss, Inc. [source] Stable isotope evidence for the consumption of millet and other plants in Bronze Age ItalyAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2009Mary Anne Tafuri Abstract Stable carbon and nitrogen isotope analysis was carried out on human and animal bones from four inland Early and Middle Bronze Age sites in Northern and Southern Italy. The main aims of the investigation were to explore the contribution of plant foods to the human diet and to examine any dietary differences between and within each of the sites. At two of the sites in Northern Italy, human and animal bones were significantly enriched in 13C. This finding was attributed to the consumption of domestic millets (Panicum miliaceum and/or Setaria italica), which are C4 pathway plants. Conversely, individuals from the two Bronze Age sites in Southern Italy were significantly depleted in 13C compared to those from the north. Here, millet was absent from the diet, and protein from C3 plants made a much greater dietary contribution than animal protein. This finding highlights the importance of cereal cultivation, most likely of wheat and barley, in the south of Italy during the Bronze Age. Overall, our results support the idea that the widespread cultivation of millet first occurred in Northern Italy, following its introduction from across the Alps in Central Europe. Finally, we found no significant differences in the stable isotope values between individuals at each site, when grouped by their sex or presence of grave goods. This leads to the conclusion that any status difference that may have existed is not reflected in the long-term dietary record, or at least not as measurable by stable isotope analysis. Am J Phys Anthropol, 2009. © 2008 Wiley-Liss, Inc. [source] | ||||||||||