• Market opportunities do not explain the ability of herders to meet livelihood objectives over winter on the Mongolian Plateau

    分类: 地球科学 >> 地球科学史 提交时间: 2020-06-22 合作期刊: 《干旱区科学》

    摘要:Drylands under pastoral land use are considered one of the most vulnerable social-ecological systems to global climate change, but the herders' abilities to adapt to the different extreme weather events have received little attention in the drylands. Herders on the Mongolian Plateau (MP; including Inner Mongolia Autonomous Region of China and Mongolia), have had a long history of adapting climatic variability and extreme weather events. However, it is unclear how changes such as increased levels of infrastructure and market integration affect the ability of herders to achieve the key livelihood objectives: the minimisation of the death and abortion rates of livestock in the winter. Here, we used remotely sensed and household survey data to map, model and explore the climate exposure and sensitivity of herders in the settled area (Inner Mongolia of China) and nomadic area (Mongolia) in the winter of 2012–2013. We aimed to quantify the multi-scaled characteristics of both climate exposure and sensitivity through the lens of key adaptive strategies utilized by herders. Our results showed that the higher levels of infrastructure and market integration, and the lower levels of remoteness on the MP did not increase the herders' ability to achieve the key livelihood objectives. Our results also suggested that exposure to the snow that is comparatively greater than the long-term average (cumulative exposure) may be more important in determining the social-ecological vulnerability than absolute exposure. We suggested that neither the risk management strategies available to these herders, nor the demographic variables, could compensate for the mode of production governing the pastoral systems. Our study could provide further evidence for the complex and scaled nature of climate exposure and sensitivity, and the results imply that any analysis of the relationship among exposure, sensitivity and vulnerability of pastoral households to climate change in the drylands will require a multi-scaled and interdisciplinary approach.

  • Restoration of brain consciousness ex vivo after circulatory death in pigs

    分类: 生物学 >> 神经生物学 分类: 医学、药学 >> 基础医学 提交时间: 2020-03-23

    摘要: 在临床实践中,大脑在心脏停跳数分钟后会出现不可逆的损伤,如果30分钟后患者仍未能成功复苏,将被宣布临床死亡。最新研究显示,在心脏停跳后数小时后,猪的大脑细胞功能仍可在体外得到恢复。然而,在离体状态下意识能否恢复尚不清楚。本研究中,我们建立了用于循环停止后大脑体外复苏的常温机械灌注技术。我们发现大脑单独灌注即能维持大脑循环、细胞结构、代谢活动和脑干功能,但不能恢复大脑意识。而在肝脏的支持下,大脑整体的电活动和意识得以恢复,大脑功能至少可以维持22小时。该技术能够使热缺血50分钟的大脑恢复意识。研究结果表明,肝脏辅助下的大脑常温机械灌注技术可以在循环停止较长时间内恢复和维持大脑的意识。