Fate and removal of antimony in response to stringent control activities after a mine tailing spill.

When tailing spill accidents occur, the risk of contamination by antimony (Sb) tailings into adjacent rivers, sediments, aquifers and soil environments is high. The Sb concentrations in water and sediment under different stringent control activities were investigated for 60 days in the Jialing River basin after a tailing spill accident. Both reservoir regulation and the construction of a temporary dam with coagulation dosing remarkably reduced the Sb levels in the river water. The increase in dissolved Sb caused by the spill was reduced from ~400 µg/L in the inflow to ~200 µg/L in the outflow by reservoir regulation. Moreover, reservoir regulation led to a high concentration of Sb in the reservoir sediment, which was difficult to remove and may cause subsequent unpredictable long-term ecological and health risks. In contrast, the Sb-enriched deposition inside the temporary dam was convenient to remove. Notably, temperature alternations between day and night in winter resulted in a large fluctuation in coagulation efficiency, which may cause the failure of stringent control projects. The results of this study suggest potential improvements to stringent control activities after mine tailing accidents to mitigate environmental impacts and prevent secondary risks.

The Cold Hardiness of Phrynocephalus erythrurus, the Lizard Living at Highest Altitude in the World.

BACKGROUND: Phrynocephalus erythrurus living at Qinghai-Tibet Plateau, is believed to be the highest lizard in the world, but we know little about how these lizards cope with very low temperatures in winter. OBJECTIVE: The aim of this study was to find the difference of the lizards before and after cold acclimatization. MATERIALS AND METHODS: In this study the limit of supercooling and inoculative freezing, the concentration of four organic osmolytes, and the activity of lactate dehydrogenase in the plasma were measured in samples shortly after capture and in other samples after 7~8 weeks of acclimatization at 2~4 degree C. RESULTS: Animals acquired an ability to undergo deeper supercooling and inoculative freezing through the course of acclimatization. We find no regular changes of the four organic osmolytes after the acclimatization. CONCLUSION: We think that this species of lizard is partly freeze-tolerant and conclude that it uses supercooling to survive in winter.

Polymorphisms of the PNPLA3 gene and their associations with chicken growth and carcass traits.

1. An F(2) resource population of Gushi chickens crossed with Anka broilers was used to investigate the genetic effects of the chicken PNPLA3 gene on growth and adipose accumulation. 2. Associations between three SNPs (g.40006G > T, g.42344T > C and g.42404A > T) and broiler traits were determined using linkage disequilibrium, haplotype construction and association analysis. 3. The g.40006G > T mutation was associated with body weights at 4, 6, 8, 10 and 12 weeks of age, carcass weight, evisceration weight and semi-evisceration weight (P < 0.05). 4. Haplotypes of the g.42344T > C and g.42404A > T mutations were associated with body weight at 12 weeks, carcass weight, evisceration weight, and semi-evisceration weight (P < 0·05) and were associated with significant dominance effects. 5. The results suggest that the PNPLA3 gene may be in linkage with the causative mutation or a QTL controlling growth traits in chickens. In contrast to human studies, the polymorphisms were not associated with fat related traits.

Ultraviolet absorbance titration for determining stability constants of humic substances with Cu(II) and Hg(II).

We describe an ultraviolet (UV) absorbance titration method that can be used to determine complexing capacities (C(L)) and conditional stability constants (logK) of humic substances (HSs) with metal ions such as Cu(II) and Hg(II). Two fulvic acids (FA) and one humic acid (HA) were used for this study. UV absorbance of HSs gradually increased with the addition of Cu(II) or Hg(II) after blank correction, and these increases followed the theoretical 1:1 (ligand:metal ion) binding model. The results from the absorbance titration calculation for HSs with Cu(II) and Hg(II) compared well with those from fluorescence quenching titration. The titration of the model compound l-tyrosine with Cu(II) proved the validity of this method, and the K and C(L) were within 2.3% and 7.4% of the fluorescence quenching titration. The results suggest that the UV absorbance titration can be used to study the binding capacities of HSs and/or dissolved organic matter (DOM) with trace metals. The advantages and disadvantages of the absorbance titration method were also discussed.