Reconstructing patterns of systemic stress in a Jomon period subadult using incremental microstructures of enamel

This study reconstructs systemic stress patterning using incremental microstructures of enamel in a subadult from the Yoshigo cemetery (3200 through 2800 BP), Aichi Prefecture, Japan, with the goal of providing an improved methodological and theoretical framework for interpreting systemic stress among Jomon people. High resolution impressions and replicas were collected for each anterior maxillary tooth. Each replica was studied under 50, 100, or 200× magnification on a measuring microscope. Perikymata spacing and enamel surface profiles were recorded using specialized software. Linear enamel hypoplasia (LEH) defects were identified as accentuated spacing in perikymata combined with a depression in the enamel surface. Each defect was placed within a chronological sequence based on decile location. Stress duration was estimated by counting the perikymata in the occlusal wall of each defect and multiplying that value by the modal periodicity for striae formation. Percentage of enamel growth disruption was estimated by dividing the number of perikymata within the occlusal wall of each matched defect by the total number of perikymata within the imbricational enamel. Eight LEH defects were chronologically matched. Chronology of LEH defects ranged between 1.2 through 3.5 years. Number of perikymata located within the occlusal wall of each defect ranged from one through 20. Estimated durations of stress ranged from 12 through 129.6 days. These durations overlapped with Neandertals, though Point Hope foragers had greater durations of stress with no overlap in interquartile ranges. Disrupted enamel growth ranged from 8.1% in the maxillary left canine to 50.7% in the maxillary right central incisor.     

Evaluating sources of variation in the identification of linear hypoplastic defects of enamel: a new quantified method

Assessment and interpretation of the presence of developmental defects of enamel formation that result from childhood experiences of growth disruption, enamel hypoplasia, is a standard part of almost any systematic bioarchaeological assessment. However, different identification methods lead to different results. This study presents a new method of defect identification that offers a quantitative criterion for establishing defect presence rather than relying solely on observer judgement. It then compares this with a standard field approach to assessing enamel hypoplasia and a non-quantified microscopic approach in order to determine (a) if traditional methods of identifying enamel hypoplasia under little or no magnification offer the same information about the experience of childhood health as methods that examine dental enamel growth microscopically, and (b) the effect of using a quantified criterion to identify enamel hypoplasia. A case study using simultaneously developing teeth in one individual is presented where observations of defect presence are made both macroscopically and microscopically and with and without this novel metric method. The results demonstrate that the chosen scale of observation is a critical variable in identifying linear hypoplastic defects of enamel. Defects that occur in the more cervical regions of a tooth are ‘missed’ by methods that rely on macroscopic observation or the unaided visual judgement of the observer. This finding has considerable implications for the interpretation of reported enamel hypoplasia prevalence.     

Reconstructing faunal migrations using intra-tooth sampling and strontium and oxygen isotope analyses: a case study of modern caribou (Rangifer tarandus granti)

Isotopic analyses of incrementally developed dental tissues can be used to reveal patterns of movement and diet in animals. However, the suitability of these methods for the reconstruction of herd movements has not yet been demonstrated. Inter-individual behavioural and isotopic variability at the herd scale, and the implications for archaeological and palaeocological applications, can only be demonstrated through the testing of modern animals. In this pilot study, dual-element isotopic profiles were created from incrementally developed dental tissues of five individuals selected from a modern herd of migratory Alaskan caribou (Rangifer tarandus granti). Enamel from second and third molars from the individuals was sequentially sampled in order to reconstruct time-series isotopic profiles. Variation in the strontium (⁸⁷Sr/⁸⁶Sr) and oxygen (δ¹⁸O_CARB) isotope ratios of sequentially sampled enamel were compared to documented herd movement patterns and local geological and environmental conditions. Four individuals displayed the same general trends, although absolute isotopic values varied. One individual displays a very different trend and may represent a behavioural outlier or an immigrant from a semi-domesticated reindeer herd. The implications of this study to herd movement reconstruction in the past are discussed.     

Extraction and sequencing of human and Neanderthal mature enamel proteins using MALDI-TOF/TOF MS

We report here the first results of a method to extract and sequence mature enamel proteins from modern human and Neanderthal tooth enamel. Using MALDI-TOF/TOF mass spectrometry and a combination of direct sequencing and peptide mass mapping we have sequenced a peptide from the tyrosine-rich amelogenin peptide (TRAP) of the X isoform of the amelogenin protein for modern and recent human samples. We also report our results from two Neanderthal enamel samples where we were also able to recover fragments of the TRAP protein, which had a similar sequence to the modern human samples.     

陕西、河南地区出土唐代釉陶器釉层剥离原因分析

釉陶器在埋藏过程中,受物理及化学等因素的影响,会产生各种病害,釉层剥离是常见的病害之一。为了更深入地了解唐代釉陶器釉层剥离的原因并为以后的保护提供科学依据,对陕西、河南地区四个遗址出土的唐代釉陶器样品进行了显微观察、成分检测、热膨胀系数分析和吸水率测试。结果显示,四个遗址中,釉面保存相对完整且剥离现象较少的是巩县黄冶窑,而铜川黄堡窑、西安醴泉坊窑和乾县懿德太子墓釉陶器釉层剥离较为严重。进一步研究表明,釉陶器胎釉热膨胀系数不匹配和胎体烧结程度过低(因此造成吸水率过高)是影响釉陶器釉层剥离的主要内在因素。研究结果可为釉陶器的后续保护工作奠定基础。     

Isotopic investigation of pre-Hispanic macaw breeding in Northwest Mexico

The pre-Hispanic settlement of Paquimé (ca. 1200–1450 AD) lay outside of urban Mesoamerica in arid northern Chihuahua, Mexico, yet the excavated remains of 322 scarlet macaws, tropical parrots whose northernmost habitat is 500 km to the south, suggest that Paquimé had relationships with distant communities. Here, carbon and oxygen stable isotope analysis of 30 macaw bones determines whether the Paquimeños actively bred these parrots or traded with Mesoamerican groups to obtain the birds. The δ¹³C values indicate that the macaws ate a diet of C₄ plants, foods that were unavailable to wild macaws. In addition, δ¹⁸O data suggest that the majority of the macaws spent their entire lives at Paquimé. We conclude that the ancient Paquimeños were in fact breeding scarlet macaws, although one bone with δ¹⁸O values outside the local range suggests that the breeders also maintained exchange ties with the source areas of the birds. By confirming that Paquimeños implemented a system of local macaw reproduction outside the Mesoamerican region itself, this analysis provides new evidence about the economic and ideological interdependence of pre-Hispanic societies in the Americas. It is also suggestive of the pre-industrial capabilities of humans to extend the natural ranges of animal species.     

Seasonality of human site occupation based on stable oxygen isotope ratios of cod otoliths

Oxygen isotope ratios (δ¹⁸O) were measured in micromilled samples of cod otoliths recovered from two Stone Age sites, one from Skoklefald, southeastern Norway and five from Skipshelleren, southwestern Norway. Discrete samples of otolith material were milled from the edge of the otolith towards the centre, each sample representing 3–4 weeks of growth. The δ¹⁸O values showed seasonal signals, covering a period 1–2 years prior to the time of capture. Isotope ratios at the edge of the otoliths, which is the material deposited at the time of fish capture, corresponded to the coldest seasonal water temperatures, in late winter or early spring. These data provide independent evidence for the season of use of the Skoklefald and Skipshelleren sites.     

Glass gilding process in medieval Syria and Egypt (13th–14th century)

Twelve gilded and enamelled Islamic glass fragments, produced in Syria or Egypt during the Ayyubid or Mamluk period, were provided by the Louvre museum for complete non-destructive analysis. The enamelling process of similar objects has been extensively studied in the last decades, but the gilding process has never been investigated in details. This paper focuses on the understanding of both the gilding process and the gold/glass adhesion mechanism. The structure, composition and thickness of the gold flakes forming the gilding decoration are measured. The complete process combining gilding and enamelling is described and the local mechanism of adhesion of gold flakes on the glass body is discussed.     

A brackish water aquatic foodweb: trophic levels and salinity gradients in the Schlei fjord, Northern Germany, in Viking and medieval times

This study serves for the definition of baseline isotopic signatures of vertebrates living in the Schlei fjord, a brackish water inlet in the north German plain, where the salinity decreases from its mouth at the Baltic Sea towards the inland locations. The Viking trade centre Haithabu and its immediate successor, the town of Schleswig, are located at opposite banks of the Schlei and constitute a settlement continuum from the 9th until the 13th century. This development not only includes a relocation of the settlement site, but also a change in economy and social structure, and witnesses the metamorphosis from an international trading locality to the rise and decline of a prototypical medieval town with town charter. In this paper, stable isotope ratios of bone collagen and bone structural carbonate of 141 vertebrate bone finds mainly of fish, birds, and sea mammals from both sites are reported to provide the baseline food web in this brackish water environment, which is the prerequisite for our ongoing studies aiming at the reconstruction of human subsistence strategies as well as the geographic origin of humans, animals, food stuffs, and raw materials in order to complete the historical picture of emerging medieval towns in a complex palaeoecosystem. In particular, we are able to show how a combination of stable isotopes from bone collagen and carbonate is capable of defining the salinity gradients in the aquatic environment.     

Developmental defects and postmortem changes in archaeological pig teeth from Fais Island,Micronesia

The study investigated developmental defects of the dental hard tissues and postmortem changes in archaeological pig molars from Fais Island, Micronesia. The developmental defects of enamel were indicative of a disturbance of the secretory stage (accentuation of the incremental pattern, occurrence of Wilson bands and of hypoplastic defects) and the maturation stage of amelogenesis (hypomineralisation). Presence of coronal cementum in an M₃ indicated a partial premature breakdown of the reduced enamel epithelium or a partial demise of the enamel organ earlier during tooth development. Developmental defects of dentine presented as accentuated Andresen lines and areas of interglobular dentine. The pattern of developmental defects in the studied molars and the fact that deciduous premolars of the pigs from Fais did not exhibit developmental defects on macroscopic inspection are consistent with the hypothesis that the tooth defects were caused by periods of severe nutritional stress occurring after weaning. Postmortem changes caused by microbial infiltration were recorded in dentine and cementum. A presumed case of soft tissue preservation in the form of presence of odontoblast processes was observed in an M¹.