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The causes of prehistoric human migrations in the drylands of the Asian interior have long been debated among multidisciplinary scholars. The Bronze Age Xiaohe settlements (ca. 4000–3300 cal yr BP) are situated in the extremely arid Tarim Basin of northwest China and exemplify a societal collapse which included a long-distance movement along river catchments. Here, we present the results of stable carbon isotope values (δ13C) of archaeobotanical remains, sedimentary faces analysis from the Tarim River catchment, and a compilation of palaeo-environmental evidence in order to investigate potential relationships between regional environmental changes and the response of prehistoric societies in this arid region. Results suggest that the early Xiaohe population was forced to migrate as a consequence of the deterioration of hydrological conditions around settlements. The decline of Xiaohe Culture occurred in the context of decreasing water availability in the basin interior due to climatic change lasting several hundred years. Results are potentially significant for the management of ecologically fragile dryland habitats, particularly the watershed terminus area, threatened by ongoing climate change, specifically in the context of the need to manage scarce water resources to promote sustainable socioeconomic development. [ABSTRACT FROM AUTHOR]

The ancient kingdom of Loulan on China’s Silk Road has disappeared for about 1500 years. Historical records have documented widespread cultivation in Loulan which supported the kingdom’s prosperity for hundreds of years. However, no farmland ruins have been found although the ancient Loulan city was discovered more than 100 years ago. In this study, remotely sensed, geomorphic and geological observations of possible farmlands in Loulan were analyzed. A wide distribution of partly preserved plots with recognizable regular and straight boundaries, the existence of crossed canals, the occurrence of a gypseous incrustation layer (GIL) overlying on the surface of farmland-like blocks, and extracted large-sized pollen grains of cultivated grass from GIL samples provide new evidence for the ancient farmlands. Field observations revealed that the upper cultivated soil layer overlaid on GIL, i.e. soil horizon A, had been wind-eroded and GIL is the ruined soil horizon B. These new findings point to a well-developed agriculture of the ancient Loulan kingdom. The size and distribution of the farmlands and the thickness of the GIL suggests that irrigation for cultivation in this currently exceedingly arid area had lasted for a long time. Fluvial and lacustrine sediments in Loulan area deposited during the about 4 to ~ 8 ka BP period, revealing that the wet Holocene optimum and two arid events of about 4 and 8 ka BP occurred in the westerlies-dominated northwest China. The Loulan kingdom period was another wet stage when the ecological environment was the typical cultivated grass of oasis near wetland. The insufficiency of water during the late period of the Loulan kingdom led the decline of irrigation agriculture and finally the renunciation of the kingdom. [ABSTRACT FROM PUBLISHER]

Non-freezing cold injury is an injury characterized by neuropathy, developing when patients expose to cold environments. Reactive oxygen species (ROS) has been shown as a contributing factor for the non-freezing cold nerve injury. However, the detailed connections between non-freezing cold nerve injury and ROS have not been described. In order to investigate the relationship between non-freezing cold nerve injury and reactive oxygen species, we study the effects of two cooling methods-the continuous cooling and the intermittent cooling with warming intervals-on rat sciatic nerves. Specifically, we assess the morphological changes and ROS production of the sciatic nerves underwent different cooling treatments. Our data shows both types of cooling methods cause nerve injury and ROS production. However, despite of identical cooling degree and duration, the sciatic nerves processed by intermittent cooling with warming intervals present more ROS production, severer reperfusion injury and pathological destructions than the sciatic nerves processed by continuous cooling. This result indicates reactive oxygen species, as a product of reperfusion, facilitates non-freezing cold nerve injury.

Objective: To explore the clinical characteristics of the lesions of spinal cord and optic nerve as the onset of neuromyelitis optica (NMO)., Methods: A total of fifty-one patients with myelitis or optic neuritis (ON) as the onset of NMO who hospitalized in our Neurology Department during October 2010 to October 2012 were enrolled in the study. Clinical presentations and MRI findings of the spinal cord and brain were studied., Results: (1) A total of 26 cases (51.0%) presented with myelitis as the index event, in which 30.8% (8/26) were the longitudinally extensive transverse myelitis (LETM) and 69.2% (18/26) were non-LETM (short segmental myelitis or non-transverse myelitis). Patients with non-LETM as the onset were found to have better prognosis than those with LETM (full recovery ratio was 13/18 vs 2/8, P < 0.05), while shorter recurrence interval of myelitis and higher recurrence frequency of events were shown in patients with non-LETM (11.1 vs 18.6 months, 3 times per year vs once per year, with all P < 0.05). (2) A total of 25 cases (49.0%) presented with ON as the index event with 24.0% (6/25) of unilateral ON and 76.0% (19/25) of bilateral ON. Patients with bilateral ON had more severe visual impairment and shorter first remission period than those with unilateral ON (P < 0.05)., Conclusion: Non-LETM and bilateral ON are the most common index demyelinating events in NMO cases.