针刺条件下单一肌梭传入神经电信号的统计分析

本文应用分离单一肌梭的方法,对在针刺条件下肌梭的传入放电进行了统计分析,同时应用快速付里叶(Fourier)变换算法对其传入放电的波形特征作功率谱分析。结果表明,针刺时肌梭传入放电的频率明显增多且趋于平稳,而留针期间,肌梭的放电频率随留时间的延长而规律性递减,表现有一定的适应现象。提示针感的强弱应是针刺>留针>去针后。功率谱分析表明,针刺前、针刺时、留针及去针后等4种情况下,单一肌梭传入放电的主要能量都集中在低频段内,针刺时略向较高频率偏移,提示针刺时肌梭中的较粗纤维活动增强。     

人体桡神经浅支支配机械感受性单位的生理学特征

实验用神经内微记录和微刺激相结合的方法,对人体桡神经浅支支配的有毛皮肤所属机械感受性单位的特征和诱发感觉的性质进行了观察。在47个感觉单位中,SA单位占74.5%,其中SAⅠ61.7%,SAⅡ12.8%,RA单位占25.5%,没有发现毛囊单位和PC单位。SA单位的平均机械阈值高于RA单位,RA和SAⅠ单位的感受野明显小于SAⅡ单位。神经内微刺激诱发感觉的性质取决于所兴奋单位的类型,RA单位产生间断的跳动感,SAⅠ单位产生持续的压感;而SAⅡ单位在单独兴奋时不产生特定的感觉。结果提示:人体桡神经浅支支配的有毛皮肤机械感受性单位的特征与无毛皮肤没有明显差别。     

Forecasting the impacts of climate change on inland waterways

Inland waterways are vulnerable to climate change as river navigation depends on water levels. Droughts can severely disrupt inland navigation services by reducing water levels either to completely non-navigable ones or to levels that oblige operators to reduce vessel load. We analyse the impacts of droughts induced by climate change using projections of river discharge data provided by eleven different climate model runs. We consider location specific characteristics by focusing the analysis on four specific locations of the Rhine and the Danube where a substantial part of the total freight activity in the European Union (EU) takes place. For the majority of the cases and scenarios considered, a decrease of the number of low water level days is projected, leading to fewer drought related disruptions in the operation of the inland waterway transport system. Although the uncertainties from the climate projections should not be neglected, the navigation sector could benefit from global warming which means that European inland waterways might be one of the few sectors where climate change can have negligible, or even positive, impact. The average economic benefit, for the cases considered, from the decrease of low water levels by the end of the century is projected to be almost €8million annually.