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21.
    
Over the last decade, Africa's natural resources have seen another rapid rise in political‐economic importance. The continent's abundant biodiversity underpins the fast‐growing (eco)tourism industry, while its rich energy resources have seen renewed attention from global powers. Obviously, these boom‐and‐bust cycles of interest in African natural resources have signified the continent's place in the capitalist world order for a long time. Yet, and despite the intense ambiguities and manifold negative consequences of this history, the conservation of Africa's biodiversity riches and the exploitation of its energy resources continue to be promoted in win‐win terms: beneficial to the continent and outsiders ‘consuming’ the resources. The paper reviews this ‘boom‐and bust’ cycle of interest in Africa's resources in the light of the recent ‘Great Financial Crisis’. It argues that an initial review of mainstream responses to the crisis shows a global ‘reflex’ that falls back on and so reinstates Africa's ‘natural place’ in the global order.  相似文献   
22.
Extended depth of focus image for phytolith analysis   总被引:1,自引:0,他引:1  
This paper proposes a new phytolith analysis method by extended depth of focus technology. The extended depth of focus image is sharp throughout by the image processing of a series of photos, while each acquisition of the original photo will be compromised and show certain parts of the specimen in and out of focus. Consequently, the extended depth of focus image is suitable for computer-assisted morphometrics analysis. Meanwhile, the extended depth of focus image can be used for three-dimensional reconstruction images. Experiments on rice husk multi-cell panel show that the three-dimensional reconstruction image method can reconstruct multiple double-peaked phytoliths at one time. We also measure the parameters of multiple double-peaked phytoliths from the reconstructed three-dimension image. Comparative experiments show that the reconstructed three-dimensional image is precise enough for rice identification. Based on the above experiments, we recommend the extended depth of focus method as a promising tool in phytolith research.  相似文献   
23.
Investigating plants used for building and craft activities is important for understanding how environments surrounding archaeological settlements were exploited, as well as for considering the social practices involved in the creation and use of plant objects. Evidence for such plant uses has been observed at many Near Eastern Neolithic sites but not widely discussed. Survival may occur in a number of ways, including as impressions in clay, and as charred or desiccated macroremains. Another, less well-known, way in which plant artifacts can be found is as silica skeletons (phytoliths). Formed by the in situ decay of plants, their analysis may tell us about taxa exploited, and locations in which plant artifacts were used or discarded. At Çatalhöyük, an abundance of silicified traces of plants used in building materials and for craft activities survive, and are found in domestic and burial contexts. Their analysis demonstrates the routine use of wild plants, especially from wetland areas, for basketry (mats, baskets and cordage) and construction, as well as the secondary use of cereal husk chaff in certain types of building materials. The numerous finds suggest that plant-based containers played an important role as an artifactual class, even after the adoption of early pottery.  相似文献   
24.
To date, limited numbers of dental calculus samples have been analyzed by researchers in diverse parts of the world. The combined analyses of these have provided some general guidelines for the analysis of calculus that is non-destructive to archaeological teeth. There is still a need for a quantitative study of large numbers of calculus samples to establish protocols, assess the level of contamination, evaluate the quantity of microfossils in dental calculus, and to compare analysis results with the literature concerning the biology of calculus formation. We analyzed dental calculus from 53 teeth from four Brazilian sambaquis. Sambaquis are the shell-mounds that were established prehistorically along the Brazilian coast. The analysis of sambaqui dental calculi shows that there are relatively high concentrations of microfossils (phytoliths and starch), mineral fragments, and charcoal in dental calculus. Mineral fragments and charcoal are possibly contaminants. The largest dental calculi have the lowest concentrations of microfossils. Biologically, this is explained by individual variation in calculus formation between people. Importantly, starch is ubiquitous in dental calculus. The starch and phytoliths show that certainly Dioscorea (yam) and Araucaria angustifolia (Paraná pine) were eaten by sambaqui people. Araceae (arum family), Ipomoea batatas (sweet potato) and Zea mays (maize) were probably in their diet.  相似文献   
25.
A rapid phytolith extraction procedure is described, that allows phytolith concentrations and morphotype assemblages to be analyzed within hours. This procedure enables the results of these analyses to be used during an archaeological excavation, in order to better understand how plants were used. The new procedure was tested using a standard phytolith extract and two experimental phytolith-sediment blends and found to be both accurate and precise. The reliability of partial slide counting was evaluated and found to be as accurate and precise as existing phytolith quantification methods. The new extraction and counting procedures were applied to an archaeological site, Tell es-Safi/Gath, Israel. The results demonstrate how information on phytolith concentrations in sediments that are available from one day to the next, can be used during an excavation to more effectively document the local features of interest and obtain better information.  相似文献   
26.
This paper summarizes phytolith analyses from four pre-Columbian agricultural raised-field sites of the coastal savannahs of French Guiana—Savane Grand Macoua, Piliwa, Bois Diable and K-VIII—and carbon isotope analyses from the first-named site. The combined phytolith and 13C isotope analyses evidence the transformation of the landscape from a relatively homogeneous wetland vegetation comprised of a mixture of C4 and C3 plants (the latter including Cyperaceae and other herbaceous monocots such as Marantaceae and Heliconia, Oryzoideae grasses, and other plants typical of frequently flooded areas) to the construction of raised fields that were dominated by C4 plants (maize and other Panicoideae grasses). Our analysis proves the utility of phytoliths for tracing the agricultural history of landscapes, showing that, as in other parts of the Central and South American lowlands, maize (Zea mays) was one important crop cultivated in raised fields. We also estimated the productivity of raised-field agriculture, showing that in combination with other subsistence activities, it certainly had the capacity to sustain sizeable populations.  相似文献   
27.
Sex determination using mandible parameters is population dependent. In order to assess which measurements better characterize sex in prehispanic individuals from the Canary Islands, we blindly contrasted the results obtained by visual inspection and osteometric measurements with those obtained by molecular sexing using amelogenin ancient DNA analysis on teeth from the same material. Unambiguous sex classification was achieved by amplification of sex specific amelogenin alleles in 56 out of 76 mandibles (73.78% of the cases). Visual inspection led to a correct diagnosis in 66.04% of cases, with a greater proportion of errors for female (54.17%) than male (17.24%) mandibles. Osteometric measurements were able to assign sex correctly in 72.2% in the best of cases (mandibular height), a proportion similar to that obtained using a discriminant function (71.2%). By logistic regression analysis, ramus breadth, index ramus breadth/ramus height and mandibular length were the parameters independently related with a mistaken diagnosis of female sex, whereas bigonial width, ramus height and mandibular length were the parameters more closely and independently related to a mistaken diagnosis of male sex. In conclusion, diagnosis based on visual examination of the mandible or on its metric measurement only serves to roughly estimate sex with an accuracy of around 70% or less, at least among the prehispanic population from Gran Canaria. Amplification of amelogenin alleles leads to unambiguous identification of male and female alleles in 73.68% of cases, at least among the prehispanic population from Gran Canaria.  相似文献   
28.
西周时期墓葬中有机质的葬具通常保存情况极为不佳,考古学信息不甚明确,因而墓葬研究中往往无法充分利用此类材料,但此类材料具有潜在的考古学研究价值。本研究以2017年度周原遗址齐镇发掘区墓葬内所出严重降解的织物为材料,利用显微技术观察残余的表皮细胞和植硅体形态,鉴定结果表明墓葬内所出织物为芦苇(Phragmites communis),符合先秦文献中对殓席的记载,主要根据《士丧礼》和《既夕礼》两篇内容,梳理了芦苇编织物在丧葬过程中的用法和可能的出土位置,以此进一步判断出土苇席的性质主要为卧席和抗席。  相似文献   
29.
为了确定大理市博物馆藏文殊菩萨木雕用材树种,分别采用木材解剖技术和DNA条形码技术对其进行比较鉴定。解剖比对结果显示,文殊菩萨木雕用材的微观构造特征与云南樟(Cinnamomum glanduliferum)标本接近,主要细胞形态特征与云南樟无显著差异,可初步鉴定文殊菩萨木雕用材树种隶属于樟科(Lauraceae)樟属,但不能确定为云南樟,因此通过采用DNA条形码进一步鉴定。DNA条形码比对结果表明,对于文殊菩萨木雕与云南樟标本鉴定的5个DNA条形码,rpoC1、rbcL和matK的分辨率低,只能将2种木材样品鉴定到属的级别;而trnH-GUG和psbA-trnH具有较高的分辨率,能将2种木材样品鉴定到云南樟的具体种;NJ系统发育分析结果表明,2种木材样品和所选的樟科树种可以准确聚类。DNA条形码技术可以实现大理市博物馆藏木雕文殊菩萨像木材种类的快速且准确鉴定。  相似文献   
30.
墓葬壁画是我国重要文化遗产,承载着灿烂的文明与古代科技,体现着当时社会先进生产力,是能让文物\"活起来\"的典型代表。壁画类文物的保护研究与价值阐释,是国家文化自信建设战略的重要组成部分。基于墓葬壁画本身材质的脆弱性以及较低的环境耐受性,目前墓葬壁画的保护手段还是以现场揭取、搬迁等异地保护方法为主。在这一过程中壁画承载的信息难免流失,保护壁画的材料亦为后续研究带来了干扰。故而,建立起一套墓葬壁画现场信息提取方法体系,在考古发掘现场第一时间提取表面信息、挖掘隐藏信息,开展综合研究十分必要。本工作参考了石窟、建筑壁画、考古现场遗迹信息提取方法,结合墓葬壁画自身特点,针对墓葬壁画信息提取不全面、不深入的问题,以多座陕西地区墓葬壁画以及四川、江西、河北、宁夏等地墓葬壁画为研究对象,开展了墓葬壁画信息提取方法研究,提出了全面的墓葬壁画现场信息提取的思路与方法。首先,开展有效环境监测,从而提出合理的小环境控制手段,以延缓壁画劣化;然后,通过有效组合各种照相技术和光谱技术,开展从宏观到微观,从可见光到多光谱全方位、多维度的画面信息提取,全面深入记录画面信息;联合多种便携检测设备,在科学选点基础上,提出由表及里、由点及面、重点关注逐层深入、互相补充的材质工艺研究思路,有效获得壁画的制作材料组成、工艺特征;最后,综合以上多重结果,通过观察与仪器检测,对壁画进行多角度、多层次病害调查,准确掌握壁画壁画病害分布、病害程度。此外提出了以研究需求与标本保存为目的各类标本采集要求与方法。墓葬壁画考古现场信息提取是现场科学保护和后续考古学研究的关键部分,其积累的大量影像资料、数据资料为壁画保护提供了支撑,为考古学研究提供了重要证据,为壁画价值的深入挖掘提供科学依据;极大地提高了考古学家对现场信息提取的重视程度,促进学科交叉融合。本研究弥补了墓葬壁画信息提取手段单一,缺乏方法体系的不足,为行业发展提供技术支持,为实现壁画文物的有效保护发挥作用。  相似文献   
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