Digital extraction: Blockchain traceability in mineral supply chains

Digital data — including technologically-mediated data generated by blockchain-enabled traceability — is performing an increasingly integral role in extractive operations, but scarce attention has been paid to the structuring effect of these digital technologies or the socio-economic spatiality of data-driven mining operations. Drawing on extensive qualitative research (interviews, participant observation, and two sets of survey data among actors relevant to these mineral supply chains), this article advances the notion of “digital extraction” to describe the collection, analysis, and instrumentalization of digital data generated under the banner of blockchain-based due diligence, chain of custody certifications, and various transparency mechanisms, situated alongside and in support of mineral extraction. The article mobilizes concepts from political geography and political ecology to argue that digital technologies of traceability in extractive processes potentially create new forms of control and exclusion or exacerbate existing social, political, and territorial dispossession through asymmetric relations of power and knowledge in mineral supply chains. Despite industry efforts to make mineral supply chains more sustainable by resorting to digital certification and traceability, the strategic uses of uncertainty, ignorance, and ambiguity undergirding blockchain-enabled traceability systems fail to challenge existing inequalities in resource use and access or fulfill the promise of transparency and accountability.     

Role of Monitoring in Historical Building Restoration: The Case of Leaning Tower of Pisa

A short summary is presented of the studies and the actions of Committees appointed in past 50 years for the Tower of Pisa. The discussion first addresses the attempts carried out during the whole history of the Tower to measure its movements and the efforts made to understand the origin and causes of its inclination. A history of foundation rotation has been also deduced by means of a precise architectural survey, which has led to a diagnosis for the inclination and its increase in time. As a consequence, several hypotheses for its stabilization have been proposed. All the measures for leaning tower stabilization need the application of observational method for their implementation. The observational method is strictly based on a comprehensive monitoring system, both described in the second part of the paper. The aims are to stress the importance of a well-conceived monitoring system and to propose the extension of concept of monitoring to construction history details. The data and actions described are from the work carried out by committees appointed by Italian Government during the second half of 20th century, in particular by the committee chaired by Professor Jamiolkowski, appointed in 1991. The authors have collaborated with this committee since 1993, and they are still in charge of the monitoring and maintenance of the Tower of Pisa.     

Improved methodology for extraction and amplification of DNA from single grains of charred wheat

Comparisons were made between two commonly used methods for the extraction of ancient DNA from charred plant remains. Using artificially charred wheat seeds, we show that silica-binding is the most efficient method for extraction of DNA. We describe a improved silica-binding procedure, including pre-incubation with N-phenacylthiazolium bromide and increased washing of bound DNA, which yields amplifiable DNA from seeds heated at 200 °C for up to 8 h, conditions which promote the formation of Maillard products which often copurify with aDNA and inhibit subsequent PCRs. We believe that this method will be effective in ancient DNA extraction with most types of charred archaeobotanical material. Both cold- and hot-start PCR procedures gave good amplicon yields with extracts prepared in this way, but cold-start PCRs also resulted in synthesis of short artefact products. Addition of bovine serum albumin to PCRs, an inert carrier substance thought to enhance amplification efficiency by binding contaminants, had no advantageous effect and in fact reduced amplicon synthesis.     

薄荷醇/石膏复合体系用于考古发掘现场临时固型提取的可行性研究

复杂而且脆弱的文物或化石的提取和搬迁是考古或化石发掘现场最常见的技术难题。采用石膏对这些文物或化石进行现场固型再提取是常用的应急性保护手段之一,对此类文物或化石的提取和搬迁具有重要作用。但石膏含有可溶盐,应用时需引入水,并大量放热,对文物或化石有潜在危害,而且石膏难以完全去除。 近年来,薄荷醇、环十二烷等可挥发性临时固型材料受到了极大关注,被越来越多地应用在发掘现场。其最大的优点就是固型材料可以通过升华轻易被去除,无残留,不会影响后续的考古研究和保护工作。但是有机物小分子固化后强度偏低,不适合较大较重文物或化石的固型提取。 针对考古发掘现场复杂脆弱而且较大、重的文物或化石的提取和搬迁需求,提出了新型临时固型材料薄荷醇和石膏复合应用的现场固型提取技术体系。本工作研究了石膏和有机小分子薄荷醇的相容性和匹配性,实验室研究结果显示薄荷醇除了在样品表面实现有效固型,还能快速在模拟样品表面形成一层致密的疏水隔离层,有效地阻止石膏加固过程中水和可溶盐的进入;而且实验数据显示石膏放热不影响薄荷醇疏水隔离层的功能。实验结果显示薄荷醇和石膏二者性能互补,有望满足发掘现场对大、重文物或化石的固型提取需求。 以新疆哈密翼龙化石的现场发掘提取为例,采用薄荷醇/石膏复合材料体系现场固型并提取一块约20 kg重的化石样品,结果证实石膏和薄荷醇复合使用技术可以很好地固型并提取较大较重的样品,同时避免了水和可溶盐对化石的破坏,而由于薄荷醇隔离层的存在,石膏的去除也非常彻底,整体固型提取效果良好。     

Invisible power,visible dispossession: The witchcraft of a subterranean pipeline

There has been a lack of attention to the role of la sorcellerie (witchcraft) and the occult in geographical work on extraction, power and resistance, despite the ways in which these epistemologies inform conceptions of power, wealth and violence. In two towns along the Chad–Cameroon Oil Pipeline, epistemologies of la sorcellerie frame understandings and critiques of the invisible actors and processes that effect the pipeline's uneven distributions of violence, wealth and risk. Far from expunging the experience(s) of extraction by erasing the pipeline's visible traces on the landscape, the oil consortium's infrastructural and discursive erasures serve to situate the pipeline within a knowledge system that associates invisible actors and materials with evil, wrongdoing, suspicion and distrust. This article addresses (i) how the production of dispersed extractive landscapes reinforce epistemologies of witchcraft by alienating the people who live within them from networks of power in ways that provoke a mistrust and jealousy that is absorbed within families and communities and (ii) the socio-political significance of this epistemological structuring of the pipeline as a logic of resistance against hydrocarbon capitalism.