Impacts of climate change and human activities on grassland vegetation variation in the Chinese Loess Plateau.

China initiated the "Grain for Green Project" in 1999 to mitigate soil erosion. The vegetation cover of the Chinese Loess Plateau, one of the most erosive regions in the world, has been greatly increased. However, studies on quantitatively investigating the climate change and human activities on vegetation coverage change were rare. In this study, spatio-temporal changes in vegetation coverage were investigated using MODIS normalized difference vegetation index (NDVI) data over 2000-2016. And a new method was introduced using Net Primary Productivity (NPP) model and relationship between NPP and NDVI to quantitatively and spatially distinguish the NDVI affected by climate change and human activities. Results showed that mean NDVI value over 2009-2016 were 14.46% greater than that over 2000-2007. In order to quantify the contribution of climate change and human activities to vegetation change, an NPP model suitable for the grassland of the Chinese Loess Plateau was identified using biomass observations from field survey and literature. The NDVI affected by climate change (NDVIclimate) was estimated by the NPP model and the relationship between NPP and NDVI. And the NDVI affected by human activities (NDVIhuman) was calculated by actual NDVI minus NDVIclimate. Comparison of the two stages showed that human activities and climate change contributed 42.35% and 57.65% respectively to the ΔNDVI on grassland in the Loess Plateau. After analysis of numerous NDVIhuman related factors, the slopes restored by the "Grain for Green Project" was considered the main influence factor of human activities.

Improved treatment of frozen red blood cells by red blood cell processing technology / 军事医学

Objective To improve the buffer for washing frozen red blood cells(RBCs)and explore the feasibility of replacing the middle buffer of 2% NaCl with 0.9% NaCl solution in the protocol of deglycerolization and the effect was evaluated.Methods Two units of RBCs separated from whole blood of healthy donors were frozen at -80℃.The thawed frozen RBCs were treated with a washing machine.On the basis of the old protocol(protocol 1),the middle buffer of 2%NaCl was replaced,and the usage of washing buffer and the washing steps were adjusted to create a new protocol(protocol 2).The quality of RBCs washed by the two protocols was evaluated.Results According to the results of the detection of RBCs treated by protocol 1 and 2: the hemoglobin contents(g)were 42.18 ±3.35 and 44.98 ±1.68,respectively,free hemoglobin contents(g/L)were 0.53 ±0.06 and 0.45 ±0.05 respectively, the residual amount of white blood cells (×107)was 1.92 ±1.04 and 1.12 ±1.12,and the osmolarities(mOsm)were 327.0 ±9.06 and 331.8 ±10.62 respectively. Sterile experiments were negative for both bacteria and fungi.The hemolysis rates(%)were 12.02 ±5.78 and 14.30 ± 5.67 respectively.The deforming abilities(%)were 21.42 ±1.45 and 21.32 ±0.84 respectively.The RBC recoveries (%)were 77.18 ±5.58 and 79.63 ±2.06 respectively.The processing time(min)was 79.60 ±0.55 and 78.80 ±1.30 respectively.There was no significant difference in the quality of frozen RBCs washed by the old protocol(protocol 1)and the new protocol(protocol 2)(P>0.05).Conclusion The quality of frozen RBCs washed by the two protocols meet national standards.