Assessing the distribution of Asian Palaeolithic sites: a predictive model of collagen degradation

Having previously shown that there is a statistically significant relationship between areas of low collagen degradation and the location of archaeological sites in Africa [K.M. Holmes, K.A. Robson Brown, W.P. Oates, M.J. Collins, Assessing the distribution of African Palaeolithic sites: a predictive model of collagen degradation, Journal of Archaeological Science 32 (2005) 157–166], we here test the applicability of the same model on Palaeolithic archaeological remains from Asia.     

Confocal laser scanning microscopy: a flexible tool for simultaneous polarization and three-dimensional fluorescence imaging of archaeological compact bone

Wide-field polarized light and epifluorescence microscopy have been used to enhance analysis of archaeological bone tissue, providing information on bone formation, modeling, pathology, preservation, age estimation, and biomechanics. Though valuable, these techniques are limited by their inability to remove out-of-focus light and view multiple levels of a sample, restricting our understanding of the three-dimensional (3-D) microarchitecture of compact bone. Modern technological advances, such as microscopic computerized tomography, allow increasing resolution in 3-D bone imaging, but do not allow fluorescence labeling or polarized-light analysis. Confocal laser scanning microscopy (CLSM) is a valuable tool for 3-D histology. However, its application to the study of compact bone is lacking, especially in archaeological and forensic sciences. The current study investigated CLSM as a tool for fluorescence and polarized-light microscopy of archaeological compact bone in order to demonstrate its advantages. Standard techniques and CLSM are compared in their suitability for imaging well preserved archaeological bones from the Dakhleh Oasis, Egypt. CLSM's high resolution, multi-channel, two- and three-dimensional capabilities augment the flexibility and creativity of compact bone imaging and have the potential to increase the accuracy of quantitative medical and anthropological histomorphometric techniques. CLSM is specifically suggested as a useful tool for the investigation of ancient bone fluorescence caused by the presence of tetracycline and/or other fluorochromes.     

Palaeoenvironmental and chronological investigations of the Magdalenian sites of Goyet Cave and Trou de Chaleux (Belgium), via stable isotope and radiocarbon analyses of horse skeletal remains

Trou de Chaleux and Goyet are caves situated less than 30 km apart in Belgium that contain stratified Magdalenian artefacts and butchered faunal remains. Published radiocarbon dates suggest that both sites were contemporaneously occupied during to the Late-glacial interstadial. It has previously been suggested that the Trou de Chaleux Late-glacial faunal remains might be slightly older than those at Goyet Cave, and that Trou de Chaleux has two phases of occupation during the Late-glacial interstadial. However, the limited number of radiocarbon dates currently available makes it impossible to determine whether the sites are truly contemporaneous, and the assessment of their absolute chronologies is complicated by a plateau in the calibration curve. In this paper, bone collagen δ¹³C and δ¹⁵N signatures of horse bones from the two sites are used to reconstruct local palaeoenvironments. We hypothesise that if occupations at the two sites were contemporaneous, the horse collagen δ¹³C and δ¹⁵N isotope signatures from both sites will be similar, since comparable carbon and nitrogen isotopic values would reflect similar diets, ecologies and environments. To provide clear dating parameters, new AMS radiocarbon determinations are also presented. Results show that horse collagen δ¹³C and δ¹⁵N isotope signatures at the two sites are different, indicating that the populations were not subject to similar diets, ecologies and environments. The new radiocarbon dates confirm that the horse bones from Trou de Chaleux date to the Late-glacial interstadial, but they also show that in Goyet Cave Horizons 1 and 2, older horse remains dating to ca. 32?000–27?000 ¹⁴C yr BP are mixed with Late-glacial horse remains. The δ¹⁵N values of the Goyet Cave horse bones radiocarbon dated to the Pleniglacial are substantially higher than those that have Late-glacial radiocarbon dates. Therefore, we now hypothesise that the majority of the horse bones isotopically analysed from Goyet Cave Horizon 1 are Pleniglacial in age. Statistical analysis of the radiocarbon dates indicates that the Late-glacial occupation at the two sites was contemporaneous, and that while there may appear to be two phases of occupation at Trou de Chaleux, this may be an artefact of the radiocarbon calibration curve.     

Stable isotope data from the early Christian catacombs of ancient Rome: new insights into the dietary habits of Rome's early Christians

This study reports on the first attempt that determines the diet of a small but conceivably representative section of Rome's early Christian community by means of δ¹³C and δ¹⁵N measurements on collagen extracted from twenty-two samples of human bone. Samples derive from the Liberian Region in the catacombs of St. Callixtus on the Appian Way—an area that has been radiocarbon dated to the period from the mid-3rd through early 5th century AD. Comparing our results to those produced for several other sites, we argue that this population's typical diet included freshwater fish. We also briefly discuss breastfeeding and the freshwater reservoir effect, to then explore the dietary, art historical, and possible sociological ramifications of our results.     

Assessing the function of early hominin bone tools

Bone tools from early hominin sites in southern Africa continue to intrigue researchers interested in the development of early human technology and cognition. Sterkfontein, Swartkrans and Drimolen have all yielded bone tools dated to between 1 and 2 Mya associated with numerous Paranthropus robustus and few early Homo remains. The bone tools are described by different authors as implements used to excavate tubers from the ground and termites from their nests, work hides and strip bark from trees. The purpose of this research was to develop a more powerful analytical tool for the study and interpretation of bone surface modifications in general, and early hominin bone tool function(s) in particular. We used an optical interferometer to scan the worn areas of a sample of bone tools from Swartkrans and Drimolen, an ethnographic collection of implements used for defleshing marula fruits, and a set used experimentally to excavate in the ground and in termite mounds. The 3D rendering of archaeological and experimental wear patterns better highlights previously described differences between these patterns, and demonstrates the pertinence of this analytical tool to visually discriminating between different bone modifications. Analysis of selected 2D and 3D roughness variables indicates that the wear pattern on the early hominin bone tools from Drimolen is significantly different from that of tuber digging, very similar to termite foraging, and not unlike marula fruit processing. Marked differences are detected between the Swartkrans and Drimolen wear patterns, which suggests that the tools from these sites may have been used with different motions, in contact with abrasive particles of different size, or in different tasks. Principal component analyses conducted on 2D and 3D variables suggest that early hominin bone tools from southern Africa may have been used to forage for termites, extract tubers in a motion parallel to the tool main axis, process fruits and conduct other, as yet unidentified, tasks.     

Archaeological collagen: Why worry about collagen diagenesis?

DNA appears to decay by random chain scission resulting in a predictable range of fragment lengths. Collagen decay has also been modelled in this same way, although it has become increasingly evident that collagen decay does not follow this same pattern. Radiocarbon and stable isotope analysis now use ultra-filtration to isolate large fragments (>30% of original polymer length) even in Pleistocene bone. How then does collagen decay? This study contrasts experimentally degraded samples with collagen extracted from forensic, archaeological and fossil bone. In experimentally degraded bone, values for amino acid and elemental (C:N) composition, bulk δ ¹³C, δ ¹⁵N, and aspartic acid racemisation (AAR) changed very little until 99% of the collagen was lost, suggesting that the collagen triple helix and polypeptide chains remained remarkably intact. This suggestion was demonstrated directly by examining the integrity of individual polypeptide chains using cyanogen bromide (CNBr) cleavage followed by SDS-PAGE electrophoresis. In ancient samples, AAR values remain remarkably stable and the pattern of CNBr-cleavage was only replaced with a smear of smaller polypeptides in the oldest (Pleistocene) bones investigated. Smearing may reflect both modification of the methionine resides (the sites of CNBr-cleavage) and/or partial hydrolysis of the collagen molecule. The findings reveal why it is not usually necessary to worry about collagen diagenesis; it is mostly intact. However, evidence of partial deterioration of the oldest bone samples suggests that alternative purification strategies may increase yields in some samples.     

Bone diagenesis in the European Holocene I: patterns and mechanisms

Diagenetic changes in archaeological bone are known to influence the data derived from such material and have thus been the subject of numerous studies. A number of general trends have been observed, but many of the processes that occur are still not fully understood. We present here the analysis of 195 bones excavated from 32 sites in five different countries from Eurasia characterized using 10 simple diagenetic parameters. The results reveal that most European Holocene archaeological bone can be categorized by only four main diagenetic states related to three distinct trajectories that describe more than 60% of the variation in these parameters. Given the potential amount of variation in the dataset the small number of diagenetic pathways is surprising, but highlights the large importance of a few key factors that influence bone diagenesis. Mercury intrusion porosimetry is a key technique for identifying modes of degradation.     

释殷墟卜辞中的“■”字——兼论“羑里”

殷墟甲骨卜辞中有一字,见于《甲骨文合集》(简称《合集》)和《殷墟花园庄东地甲骨划》[1](简称     

湿度对骨质文物的影响及最佳存放湿度的研究

系统考察了在不同湿度下,老化400天后骨样的抗弯强度、色差值、显微形态、元素含量、尺寸和重量各项指标的变化,找出了湿度对骨质物影响的规律,从而确定60％湿度为骨质物的最佳存放湿度。     

氢氘交换用于古代皮革胶原蛋白微观结构的研究

皮革文物由动物皮制作而成,是人类在认识和改造自然过程中留下的宝贵财富,是研究古代社会历史的珍贵实物史料。皮革作为一种天然有机高分子材料,其主要组成成分胶原蛋白易受保存环境影响发生变性劣化,研究胶原蛋白的微观结构对于了解古代皮革的劣化具有非常重要的意义。氢氘交换技术(HDX)基于蛋白质中不稳定的氢原子会与氘原子发生交换的原理常被用于蛋白质结构研究,但其用于古代皮革胶原蛋白的结构研究却鲜见报道。本研究采用HDX结合傅里叶变换红外光谱技术(FTIR),对现代皮革、人工老化皮革和古代皮革胶原蛋白的三股螺旋结构进行了分析和比较研究,通过特征吸收峰的位置和氘代率来表征胶原蛋白微观结构的变化。研究结果表明现代皮革胶原蛋白的三股螺旋结构保存完整,氘原子难以进入其中与主链氨基氢原子发生交换反应,氘代率为32.09%。而人工老化皮革和古代皮革在劣化过程中胶原蛋白主链酰胺氢的溶剂可及性以及其参与形成的氢键发生了变化,维系三螺旋结构稳定的氢键断裂,三股螺旋结构发生一定程度解体,位于螺旋结构中心的甘氨酸暴露出来,增大了骨架酰胺氢的溶剂可及性,结构变得松散不稳定,加快了氢氘交换速率,更容易发生氢氘交换反应。三个古代皮革样品中Old3的氘代率最低,氘代率为65.87%,其三股螺旋结构被破坏程度最小,劣化程度也最轻。与之前已报道的氢氘交换研究蛋白质结构的文献相比,在以下方面做出拓展:一是通过分析胶原蛋白特征结构,指出主链氨基氢尤其是甘氨酸的酰胺氢是与氘原子发生交换的主要对象。二是根据氢氘交换后相应基团质量数发生变化会引起伸缩振动频率的变化这一特点,选择傅里叶变换红外光谱中胶原蛋白的酰胺A带来作为氢氘交换反应的表征工具,通过特征峰的位置和氘代率来量化氢氘交换程度。本研究将氢氘交换技术与傅里叶变换红外光谱技术相结合,引入到皮革文物胶原蛋白结构的研究中,有助于深刻理解皮革文物劣化机理,为胶原蛋白微观结构的研究和皮革文物劣化程度分析提供了一种新的方法和研究思路。