Mice with Mutation in Dynein Heavy Chain 1 Do Not Share the Same Tau Expression Pattern with Mice with SOD1-Related Motor Neuron Disease

Due to controversy about the involvement of Dync1h1 mutation in pathogenesis of motor neuron disease, we investigated expression of tau protein in transgenic hybrid mice with Dync1h1 (so-called Cra1/+), SOD1G93A (SOD1/+), double (Cra1/SOD1) mutations and wild-type controls. Total tau-mRNA and isoforms 0, 1 and 2 N expression was studied in frontal cortex, hippocampus, spinal cord and cerebellum of presymptomatic and symptomatic animals (age 70, 140 and 365 days). The most significant differences were found in brain cortex and cerebellum, but not in hippocampus and spinal cord. There were less changes in Cra1/SOD1 double heterozygotes compared to mice harboring single mutations. The differences in total tau expression and in profile of its isoforms between Cra1/+ and SOD1/+ transgenics indicate a distinct pathogenic entity of these two conditions

The impact of hydrogeochemical processes on karst groundwater quality in arid and semiarid area: a case study in the Liulin spring area, north China

Karst groundwater is the major source of water supply for economic development and drinking water in Liulin spring area, north China. Thus, karst groundwater quality and its variation have aroused wide public concern. The primary hydrogeochemical processes that dominate karst groundwater quality, including dissolution of carbonate rocks and evaporite, mixing, and dedolomitization, are analyzed by hydrogeochemical method in combination with multivariate statistical theory and computer simulation technology. The results show that the redox state of groundwater environment transforms gradually from oxidation state to reducing state with increasing temperature and total dissolved solids (TDS) and decreasing pH value along flow path. The hydrogeochemical types of groundwater range from HCO3-Ca·Mg to Cl·SO4-Na. The Ca2+, Mg2+, and HCO3 − in karst groundwater mainly originate from dissolution of calcite and dolomite. Dissolution of calcite occurs in infiltration of rainfall into soils and unsaturated zones and then reaches to saturation before arriving groundwater level. Though saturation index of dolomite (SID) is greater than 0 in most of the samples, dolomite still dissolves along flow path due to the dedolomitization. The SO4 2− derives basically from the dissolution of gypsum rather than oxidation of pyrite. The dissolution of gypsum causes dedolomitization that increases the concentrations of Ca2+, Mg2+, and SO4 2− while the concentration of HCO3 − has smaller changes. The concentrations of Na+ and Cl− are mainly controlled by dissolution of halite. The enrichment of Na+ relative to Cl− in most samples may result from leakage of surface water enriched Na+ and dissolution of mirabilte fragments