Essentials in the use of mycolic acid biomarkers for tuberculosis detection: response to “High-throughput mass spectrometric analysis of 1400-year-old mycolic acids as biomarkers for ancient tuberculosis infection” by

High molecular weight long-chain mycolic acids are key structural components of the cell envelope of Mycobacterium tuberculosis and they are established as biomarkers for the identification of both ancient and modern tuberculosis. Mycolic acids from M. tuberculosis have a characteristic profile, reflecting contributions from five major distinct homologous series of mycolate structural types. Diagnosis of tuberculosis in archaeological material, using mycolic acid biomarkers, depends on objective recognition of the key characteristic mycolic acid components. A recent article in this journal claimed that tuberculosis could be confirmed in ancient bones by high throughput mass spectrometric analysis of mycolic acids. Scrutiny of the data presented reveals no convincing evidence for the presence of mycolic acids, characteristic of the M. tuberculosis complex, in the skeletal remains examined. This communication reviews the essential criteria necessary for positive tuberculosis diagnosis, using mycolic acids.     

Quantifying tomb geometries in resistivity images using watershed algorithms

Quantifying the geometries (defined here as width, height and depth of burial) of archeological structures within resistivity models produced as a result of the regularization constraints used in most inversion algorithms is difficult, especially when structures are closely spaced. Here we apply the watershed by simulated immersion method of boundary detection to smooth 2D resistivity images generated for synthetic and field data over 3D targets. The synthetic studies include a single cavity model, a model for two widely spaced cavities (spacing ? unit electrode spacing) and a model for two closely spaced cavities (spacing < unit electrode spacing). We also examine a single-cavity model where a relatively resistive overburden, common at archaeological sites in Egypt, is included. In the case of the single cavity models, the maximum error for any geometries are 18% for the model without the resistive overburden and 10% for the model where the overburden is included, whereas it increases to 24% for the widely spaced model and 40% for the closely spaced model. Despite, the higher errors in the closely spaced cavity model, application of the algorithm confirms the presence of two features, which is not ascertainable from the smooth resistivity images. Boundaries detected with the watershed algorithm are subsequently used to define a disconnect in the regularization, resulting in a markedly improved estimate of the resistivity structure (particularly for the closely spaced cavity model) in a second inversion step using the model obtained from the smoothness constraint inversion as the starting model. This revised resistivity model also results in a lower root-mean-square (rms) misfit between measured and theoretical data, and between synthetic and inverted models. We demonstrate how the method can be applied on images from the archaeological site at Qurnet Murai, Luxor City Egypt.     

Current Research on the Gulf Coast of Mexico

The Gulf Coast of Mesoamerica is a culturally and environmentally heterogeneous area that encompasses the lowlands along the Gulf of Mexico as well as rugged inland highlands. Blessed with a wealth of valued resources and a favorable geographical setting, the pre-Hispanic Gulf Coast played a critical role as a cultural and economic crossroads, and its cultures contributed vital elements to other Mesoamerican traditions. Gulf Coast archaeology currently is experiencing the most active period in its history. This recent research underscores the diversity and dynamism of the area's cultures and environment. An enormous expansion of settlement pattern studies reveals considerable diversity in sociopolitical organization, urbanism, and human–land relationships. A second important trend focuses on documenting and understanding variation in craft production and exchange systems. A third is the continuing emphasis on interregional interaction through all time periods. These three foci merge in a growing interest in variation and change in Gulf Coast political economies. Future research will need to incorporate theoretical perspectives that focus on the generation of cultural variation, including agency-based models of technological choice and political economy, as well as those, like Darwinian approaches, that emphasize the differential persistence of variation.     

Late Postclassic lowland Maya archaeology

The archaeology of the Late Postclassic lowland Maya (ca. A.D. 1200–1517) is summarized and reviewed. The history of past research is outlined, and investigations on topics of major scholarly concern are discussed. The current data allow us to present an approximate reconstruction of the events and processes that characterize the period, although the information on many areas and topics is still fragmentary. Research in Maya archaeology has focused heavily on the more spectacular developments of earlier periods, creating the impression that the last few centuries of the prehispanic era were a time of disorganization and decline. New data and interpretations indicate that the Late Postclassic was a dynamic period in which the lowland Maya were moving in new directions, restructuring their society and worldview.     

从闽台动物化石看两岸亲缘关系

祖国大陆与台湾的历史关系可追溯到人类历史的早期阶段——旧石器时代,从对闽台鹿角化石的考古研究,发现4万年前台湾海峡已有古人类活动的遗迹,而闽南东山岛就是古代连接两岸的一个桥梁。     

江苏史前考古的发现和研究

近50年来,江苏境内发现了许多旧石器时代和新石器时代的文化遗址,对这些史前文化遗址按文化区域阐析文化性质、文化时代和年代,并提出江苏史前考古今后需要探索的问题。     

中国的"原史时代"

本文由西方对"原史时代"的界定,讨论中国原史时代的定义,以及考古学在原史时代研究的地位.由西方对原史时代的定义考察中国古史,认为中国的原史时代的时间段应定于文献所记载的夏至西周晚期,考古学上的龙山时代至西周晚期;而中国原史时代的研究工作是对以中原为中心,兼及与之有联系的各种族群、文化进行全方面的、多学科的综合性研究.     

14C年代框架与三代考古学文化分期--夏商周断代工程课题研究札记

夏商周断代工程采用系列样品进行14C年代测定,得出了夏商西周的年代框架,与考古遗址相对应,解决了三代考古学的分期.登封王城岗古城约为公元前2070年,即夏的起始年代.偃师商城始建于公元前1600年,郑州商城始建于公元前1580年,前者早于后者,偃师商城遂成为夏商分界的界标.就作为都城而言,郑州商城开始作为王都的时间比起偃师商城开始作为王都的时间要晚得更多.     

X光照相技术在文物及考古学研究中的应用

X光照相方法的无损特性,就决定了这一技术适合被用于研究物这一特殊对象。本通过具体实例介绍了X光照相技术在物及考古学研究中的应用：可以反映不同材质物的保存状况,揭示被锈蚀物覆盖的铭及纹饰,显示古代器物的工艺痕迹,有助于考古出土物线图的绘制等。     

柬埔寨吴哥古迹茶胶寺考古工作纪要

2011年以来对柬埔寨吴哥古迹茶胶寺开展了多次考古调查和发掘工作,本文主要对2013年7月底前所取得的阶段性考古成果择其要记述,期待对茶胶寺的研究和保护工作逐步走向深入。