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Pastoral nomadic regional confederations, states, and empires have assumed a prominent place in the histories of the Eurasian steppe zone; however, anthropological theory devoted to understanding these political systems is still debated and relatively inchoate. A major question concerns the techniques of political integration that might have brought together dispersed mobile herders under the aegis of these complex, large-scale steppe polities. The first such polity in East Asia, the Xiongnu state (c. 250 BC–150 AD) of Mongolia, has been characterized as a polity built by mobile herders, but in fact the steppe populations of this period followed quite diverse lifeways. Most notably, the establishment of more permanent settlements for craft and agricultural production has complicated the typical narrative of the pastoral nomadic eastern steppe. This study considers ways to conceptualize these interesting variations in lifeway during the Xiongnu period and raises the question of how they might have promoted a novel Xiongnu political order. We analyze transformations within the Egiin Gol valley of northern Mongolia to better understand the organizational, productive, and settlement dynamics and present the first regional landscape perspective on the local transformations incurred by the creation of a Xiongnu agricultural hub. To understand these radical changes with respect to the long-term pastoral nomadic and hunting-gathering traditions of the valley’s inhabitants, Salzman’s flexibility-based model of multiresource pastoralism is of great use. Egiin Gol valley transformations indeed attest to a scale of political economy far beyond the bounds of this local area and suggest an innovative role for indigenous farming in Eurasian steppe polity building. 

Much work already exists on algorithm visualization—the graphical representation of an algorithm’s behavior—and its benefits for student learning. Visualization, however, offers limited benefit for students with visual impairments. This paper explores algorithm sonification—the representation of an algorithm’s behavior using sound. To simplify the creation of sonifications for modern algorithms, this paper presents a new Thread Safe Audio Library (TSAL). To illustrate how to create sonifications, the authors have added TSAL calls to four common sorting algorithm implementations, so that as the program accesses a value being sorted, the program plays a tone whose pitch is scaled to that value’s magnitude. In the resulting sonifications, one can (in real time) hear the behavioral differences of the different sorting algorithms as they run, and directly experience how fast (or slow) the algorithms sort the same sequence, compared to one another. This paper presents experimental evidence that the sonifications improve students’ long-term recall of the four sorting algorithms’ relative speeds. The paper also discusses other potential uses of sonification. 

In terms of producing new advances in sustainable nanomaterials, cation exchange (CE) of post-processed colloidal nanocrystals (NCs) has opened new avenues towards producing non-toxic energy materials via simple chemical techniques. The main processes governing CE can be explained by considering hard/soft acid/base theory, but the detailed mechanism of CE, however, has been debated and has been attributed to both diffusion and vacancy processes. In this work, we have performed in situ x-ray absorption spectroscopy to further understand the mechanism of the CE of copper in solution phase CdSe NCs. The x-ray data indicates clear isosbestic points, suggestive of cooperative behavior as previously observed via optical spectroscopy. Examination of the extended x-ray absorption fine structure data points to the observation of interstitial impurities during the initial stages of CE, suggesting the diffusion process is the fundamental mechanism of CE in this system.

 

Studies of the Eurasian Bronze Age have tended to emphasise the homogeneity of social and political processes across the Steppe, evidenced by a common ‘package’ of practices and material culture. The Dornod Mongol Survey examines the major stone monumental forms and associated features of the Ulaanzuukh mortuary tradition of the Gobi region of Mongolia. Combining evidence for mortuary and ritual practices, ceramic traditions and new radiocarbon dates, the authors argue that the appearance of the earliest Bronze Age cultures in this region represents a disparate collection of local, regional and inter-regional expressions that challenge the established narrative of a ‘standard’ Eurasian Bronze Age.