Stable isotope ratio analysis of breastfeeding and weaning practices of children from medieval Fishergate House York,UK

Rib collagen of 51 juveniles and 11 adult females from the late medieval Fishergate House cemetery site (York, UK) were analyzed using nitrogen and carbon stable isotope ratio analysis to determine the weaning age for this population and to reconstruct diet. The juveniles' ages ranged from fetal to 5–6 years, while the females were of reproductive age. Previous researchers suggested that the children from Fishergate House might have been weaned later than the medieval British norm of 2 years, based on a mortality peak at 4–6 years of age. The results show weaning was complete by 2 years of age, agreeing with previous British weaning studies. The adult female δ¹⁵N values have a mean of 11.4‰ ± 1.1‰ and the δ¹³C values have a mean of ?19.4‰ ± 0.4‰. These findings are consistent with previous isotopic studies of female diet in York during this period, though slightly lower. The weaned juvenile nitrogen values were found to be higher than the adult females (12.4‰ ± 1.0‰ for δ¹⁵N and ?19.7‰ ± 0.5‰ for δ¹³C), which might indicate a dependence on higher trophic level proteins such as marine fish or pork. Marine fish is considered a high status food and children are considered low‐status individuals at this time, making this a particularly interesting finding. Weaning does not appear to coincide with peak mortality, suggesting environment factors may be playing a larger role in child mortality at Fishergate House. Am J Phys Anthropol 152:407–416, 2013. © 2013 Wiley Periodicals, Inc.     

降水稳定同位素研究的历史与现状——基于文献计量学及网络分析方法

降水稳定同位素可以揭示降水的不同水汽来源和水汽的季节转换。通过建立降水稳定同位素与不同气象要素的关系,可为区域水资源管理甚至可为生态修复中的植被恢复状态的研究提供重要的背景数据。为揭示降水稳定同位素研究的发展现状,基于文献计量学以及网络分析方法运用Citespace软件对1990—2017年Web of Science核心数据库中降水稳定同位素的相关文献进行可视化统计分析。发现降水稳定同位素相关的文献数量在呈逐年上升趋势,主要分布在地质、气象与大气科学、海洋学、湖泊沼泽学、古生物学等相关学科,美国、中国、德国、加拿大等国家以及中国科学院、美国地质调查局等研究机构文章数量较多,表现出较强的科研实力。利用Citespace软件绘制了降水稳定同位素研究相关文献的共被引、研究作者的共被引等知识图谱,对该研究领域知识基础及核心作者的影响力进行了探讨。图谱显示,2007年以来,Yao T、Risi C、Tian L等对降水稳定同位素的研究的推进起到了重要的推动作用。最后对该研究领域的关键词与词频等进行分析,绘制出降水稳定同位素研究领域的研究热点演进脉络,并确定leaf water、Tibetan Plateau、cellulose、environmental change、tree ring、atmospheric circulation、groundwater recharge、hydrograph separation等即将成为研究的新热点。近几年来,虽然研究的文章数量在逐年增加,但是核心作者及代表作品较少,与社会的实际生产应用结合度不足。在未来研究中在注重方法的更新的同时可考虑与社会生产实际相结合。     

Non-lethal sampling for stable isotope analysis of pike Esox lucius: how mucus,scale and fin tissue compare to muscle

Stable isotope analysis (SIA) was used to examine the isotopic relationships between dorsal muscle and fin, scale and epidermal mucus in pike Esox lucius. δ¹³C and δ¹⁵N varied predictably within each tissue pairing, with conversion factors calculated for the surrogate tissues, enabling their application to the non-lethal sampling of E. lucius for SIA.     

基于碳、氮稳定同位素研究胶州湾普氏栉虾虎鱼的摄食习性

普氏栉虾虎鱼属于小型暖温性底层鱼类,是胶州湾鱼类群落中的优势种之一,在胶州湾食物网和生态系统中发挥着重要作用.本文应用碳、氮稳定同位素技术,基于胶州湾渔业资源底拖网调查采集的样品,对普氏栉虾虎鱼的摄食习性进行了研究.结果表明: 胶州湾普氏栉虾虎鱼的δ¹⁵N值范围为11.24‰～13.99‰,平均值为(12.70±0.70)‰,δ¹³C值范围为-20.67‰～-18.46‰,平均值为(-19.08±0.36)‰;各体长组的营养级范围为3.49～3.76,平均营养级为(3.62±0.21),其δ¹⁵N值和营养级与体长呈显著负相关,δ¹³C值与体长无显著相关性.普氏栉虾虎鱼摄食的主要饵料生物类群为多毛类、虾类和软体动物,浮游动物和颗粒有机物(POM)的饵料贡献率较小.聚类分析结果表明,普氏栉虾虎鱼各体长组食物组成的相似性均在92%以上,相似性较高,说明其摄食习性随体长变化无明显差异.普氏栉虾虎鱼在胶州湾生态系统中属于中级消费者,其摄食各饵料生物类群比例的变化可能是其营养级与体长呈负相关关系的主要原因.     

基于胃含物和稳定同位素研究海州湾长蛇鲻的摄食习性

长蛇鲻(Saurida elongate)为温水性近海底栖鱼类,是目前海州湾的优势鱼种之一,在海州湾食物网中占据重要地位。本研究基于海州湾底拖网调查采集的样品,结合胃含物分析和碳、氮稳定同位素技术,分析了长蛇鲻的摄食习性。结果表明: 海州湾长蛇鲻摄食的主要饵料生物为戴氏赤虾、枪乌贼、长丝虾虎鱼、鳀、六丝钝尾虾虎鱼、细条天竺鲷、尖海龙和绯鱼衔。其δ¹³C值范围在-19.39‰～-16.23‰之间,平均值为(-18.01±0.85)‰,与体长无显著相关性;δ¹⁵N值范围在9.56‰～13.36‰之间,平均值为(11.77±0.86)‰,与体长呈显著正相关。长蛇鲻不同体长组的饵料生物贡献度差异较大,随着体长增加,其捕食能力增强、摄食器官逐渐完善、摄食饵料生物的比例发生变化,可能是导致其摄食习性随体长变化的主要原因。本研究有助于深入了解海州湾长蛇鲻的摄食生态,为海州湾食物网营养动力学研究提供了基础资料。     

Monitoring uptake and contents of Mg,Ca and K in Norway spruce as influenced by pH and Al,using microprobe analysis and stable isotope labelling

In a model system using intact spruce trees (Picea abies [L.] Karst.) we followed the path of magnesium, calcium and potassium during uptake into the root and during long-range transport into the shoot, by multiple stable isotope labelling. The roots of two- and three-year-old spruce trees originating from soil culture were removed from the soil and, in part or in toto, exposed to labelling solutions containing the stable isotopes ²⁵Mg or ²⁶Mg, ⁴¹K and ⁴²Ca or ⁴⁴Ca. Optical-emission-spectroscopy (ICP-OES) of plant fractions and labelling solutions was combined with the quantitative analysis of stable isotope ratios in sections of shock frozen, cryosubstituted material using the laser-microprobe-mass-analyser (LAMMA). This combination allowed us to distinguish, both in bulk samples and on the cellular level between (i) the fraction of elements originally present in the plant before the start of the labelling, (ii) the material taken up from the labelling solution into the plant and (iii) any material released by the plant into the labelling solution.In single-root labelling experiments, roots of three-year-old spruce trees, grown in nursery soil, were exposed to various pH conditions. The exchange of Mg and Ca with the labelling solution was nearly 100% in the cell walls of the mycorrhized finest roots. This exchange was only slightly affected by a step down to pH 3.5. The absolute Mg and Ca content in the cell walls was moderately reduced by incubation at pH 3.5 and strongly reduced in the presence of Al at this pH. After a pH 3.5 and 2 mM Al treatment we found Al in the xylem cell walls and the cortex cell lumina at elevated concentrations. To analyse the combined effect of high Al and high proton concentrations on the long-range transport, we used a split-root system. The root mass of an intact two-year-old spruce tree, grown in mineral soil, was divided into even parts and both halves incubated in solutions with two sets of different stable isotopes of Mg and Ca (side A: no Al, ²⁵Mg and ⁴²Ca; side B: +Al, ²⁶Mg and ⁴⁴Ca) and ⁴¹K on both sides. We observed a large uptake of Mg, Ca and K into the plant and a pronounced release. The net uptake of all three elements was lower from the Al-doted solution. In cross-sections of the apical shoot we found after seven-day labelling period about 60–70% of the Mg and Ca and 30% of the K content in the xylem cell walls originating from both labelling solutions. The clear majority of the Mg and Ca label originated from the Al-doted side.     

基于稳定同位素技术的辽宁双台河口保护区黑嘴鸥（Larus saundersi）食性研究

稳定同位素分析是开展濒危鸟类食性研究的现代化手段,该方法避免了传统食性研究只能反映鸟类瞬时取食的弊端,而反映鸟类长时间取食的同化比例。2014年6月收集了辽宁双台河口黑嘴鸥6种潜在食源213份样品,幼鸟血样10份,幼鸟羽毛27份,成鸟羽毛17份。稳定碳氮(δ~(13)C和δ~(15)N)同位素分析结果表明:(1)成、幼鸟羽毛稳定碳同位素(δ~(13)C)差异显著,表明幼鸟与成鸟羽毛反映的食性信息不同。(2)疾病和死亡幼鸟羽毛的稳定碳氮同位素值与健康幼鸟均无显著性差异,幼鸟血液和羽毛同位素值之间也无显著差异;表明利用疾病和死亡幼鸟的羽毛样品可以替代损伤性采集血液样品,开展稳定同位素分析。(3)幼鸟血液和羽毛样品反映黑嘴鸥食性信息基本一致。其中泥螺(Bullacta exarata)和沙蚕(Nereis succinea)是其主要食源,各自贡献率均超过31.20%;其次为矛尾刺虾虎鱼(Synechogobius hasta)(12.86%、14.49%)、宽身大眼蟹(Macrophthalmus dilatatum)(9.19%、8.08%)和天津厚蟹(Helice tientsinensis)(7.48%、6.00%)。在天然湿地持续减少和退化条件下,研究结果为黑嘴鸥繁殖的人工湿地中食源物种构建、恢复与管理提供了科学依据。     

Carbon and nitrogen isotope fractionation of amino acids in an avian marine predator,the gentoo penguin (Pygoscelis papua)

Compound‐specific stable isotope analysis (CSIA) of amino acids (AA) has rapidly become a powerful tool in studies of food web architecture, resource use, and biogeochemical cycling. However, applications to avian ecology have been limited because no controlled studies have examined the patterns in AA isotope fractionation in birds. We conducted a controlled CSIA feeding experiment on an avian species, the gentoo penguin (Pygoscelis papua), to examine patterns in individual AA carbon and nitrogen stable isotope fractionation between diet (D) and consumer (C) (Δ¹³C_C‐D and Δ¹⁵N_C‐D, respectively). We found that essential AA δ¹³C values and source AA δ¹⁵N values in feathers showed minimal trophic fractionation between diet and consumer, providing independent but complimentary archival proxies for primary producers and nitrogen sources respectively, at the base of food webs supporting penguins. Variations in nonessential AA Δ¹³C_C‐D values reflected differences in macromolecule sources used for biosynthesis (e.g., protein vs. lipids) and provided a metric to assess resource utilization. The avian‐specific nitrogen trophic discrimination factor (TDF_Glu‐Phe = 3.5 ± 0.4‰) that we calculated from the difference in trophic fractionation (Δ¹⁵N_C‐D) of glutamic acid and phenylalanine was significantly lower than the conventional literature value of 7.6‰. Trophic positions of five species of wild penguins calculated using a multi‐TDF_Glu‐Phe equation with the avian‐specific TDF_Glu‐Phe value from our experiment provided estimates that were more ecologically realistic than estimates using a single TDF_Glu‐Phe of 7.6‰ from the previous literature. Our results provide a quantitative, mechanistic framework for the use of CSIA in nonlethal, archival feathers to study the movement and foraging ecology of avian consumers.     

Ear photosynthesis, carbon isotope discrimination and the contribution of respiratory CO2 to differences in grain mass in durum wheat

The role of ear photosynthesis in grain filling was studied in a number of durum wheat (Triticum turgidum var durum L.) landraces and varieties from the Middle East, North Africa, and from the collections of ‘Institut National de la Recherche Agronomique’ (INRA, France) and ‘Centro International de Mejora de Maiz y Trigo’ (CIMMYT, Mexico). Plants were grown in the field in a Mediterranean climate. Flag leaves (blade plus sheath) and ears were kept in the dark from 1 week after anthesis to maturity which reduced grain weight by 22.4% and 59.0%, respectively. In a further experiment, the carbon isotope discrimination ratio (Δ) of ear bracts, awns and flag leaves was measured on samples taken at anthesis and on mature kernels. The mean value of Δ for the water soluble fraction of bracts (17.0‰) and awns (17.7‰) were lower than those of leaves (19.5‰) and fairly similar to those of kernels (17.4‰) averaged across all genotypes. Data indicate that most of the photosynthates in the grain come from ear parts and not from flag leaves. In addition, a higher water use efficiency (WUE) of ear parts than of the flag leaf is suggested by their lower Δ values. Gas exchange in ears and flag leaves was measured during grain filling. Averaged over all genotypes, CO₂ diffusive conductance was about five times higher in the flag leaf than in the spike (with distal portions of awns outside the photosynthetic chamber) 2 weeks after anthesis. In absolute terms, the dark respiration rate (R_d) was greater than the net photosynthesis rate (P_n) by a factor of 1.74 in the spike, whereas R_d was much smaller, only 22.1, 65.7 and 24.8% of P_n in blade, sheath and awns, respectively. Data indicate that photosynthesis, and hence the water use efficiency (photosynthesis/transpiration), is greatly underestimated in ears because of the high rates of respiration which diminish the measured rates of net CO₂ exchange. Results of ¹³C discrimination and gas exchange show that genotypes from North Africa have higher WUE than those from the Middle East. The high R_d values of ears as well as their low diffusive conductance suggest that CO₂ from respiration may be used as source of carbon for ear photosynthesis. In the same way, the anatomy of glumes, for example, supports the role of bracts using internal CO₂ as source of photosynthesis. In the first experiment, the Δ in mature grains from culms with darkened ears compared with control culms provided further evidence in support of this hypothesis. Thus, the Δ from kernels of control plants was 0.40 higher than that from ear-darkened plants, probably because of some degree of refixation (recycling) of respired CO₂ in the grains.     

河南淇县宋庄东周墓地人骨稳定同位素分析——东周贵族与殉人食谱初探

淇县宋庄东周墓地出土贵族和殉人骨骼遗存的稳定同位素分析是国内首例针对东周社会分化背景下不同社会阶层先民开展的食谱研究.稳定碳氮同位素分析结果表明,贵族阶层在主粮和肉食方面与殉人群体明显不同.贵族几乎完全以粟为主粮,食物中肉类含量很高;而殉人阶层整体食肉水平较低,主粮的内部差异显著,大部分个体都不同程度的食用了当时不受青...