高锰酸钾及氯化锰对日本青鳉的急、慢性毒性(Toxic Effects of Potassium Permanganate and Manganese Chloride on the Early Life Stage of Japanese Medaka（Oryzias latipes）)

饮用水生产中投加高锰酸钾可能引起高锰酸钾及其副产物二价锰的毒性效应.利用日本青鳉的胚胎-幼鱼发育阶段评价了以高锰酸钾为预氧化剂的饮用水生产工艺安全性.结果表明,高锰酸钾对日本青鳉的LC50-96h为1.48mg·L-1.慢性暴露中,对孵化时间影响的最低可观察效应浓度(LOEC30d)为0.1mg·L-1;暴露于0.4mg·L-1的高锰酸钾对30d后日本青鳉的体长、体重、累计死亡率均有显著影响,但对孵化率率无显著影响.氯化锰(Mn2+)对日本青鳉的LC50-96h为550mg·L-1,对体重影响的LOEC30d为3.2mg·L-1.当高锰酸钾的使用浓度在0.5～1.5mg·L-1之间,其在滤后水中的高锰酸钾残余浓度低于检出限,而降解中间体产物Mn2+浓度小于0.5mg·L-1,均低于本文报道的LOECs数值.     

A simulation model for Japanese sardine (Sardinops melanostictus) migrations in the western North Pacific

A two-dimensional individual-based model coupled with fish bioenergetics was developed to simulate migration and growth of Japanese sardine (Sardinops melanostictus) in the western North Pacific. In the model, fish movement is controlled by feeding and spawning migrations with passive transport by simulated ocean current. Feeding migration was assumed to be governed by search for local optimal habitats, which is estimated by the spatial distribution of net growth rate of a sardine bioenergetics model. The forage density is one of the most important factors which determines the geographical distributions of Japanese sardine during their feeding migrations. Spawning migration was modeled by an artificial neural network (ANN) with an input layer composed of five neurons that receive environmental information (surface temperature, temperature change experienced, current speed, day length and distance from land). Once the weight of the ANN was determined, the fish movement was solved by combining with the feeding migration model. To obtain the weights of the ANN, three experiments were conducted in which (1) the ANN was trained with back propagation (BP) method with optimum training data, (2) genetic algorithm (GA) was used to adjust the weights and (3) the weights of the ANN were decided by the GA with BP, respectively. BP is a supervised learning technique for training ANNs. GA is a search technique used in computing to find approximate solutions, such as optimization of parameters. Condition factor of sardine in the model is used as a factor of optimization in the GA works. The methods using only BP or GA did not work to search the appropriate weights in the ANN for spawning migration. In the third method, which is a combined approach of GA with BP, the model reproduced the most realistic spawning migration of Japanese sardine. The changes in temperature and day length are important factors for the orientation cues of Japanese sardine according to the sensitivity analysis of the weights of the ANN.     

Effects of Arbuscular mycorrhizal fungi isolated from white clovers (Trifolium repens L) on soil bacteria and fungi

White clover potted experiments were performed to investigate the effects of seven indigenous arbuscular mycorrhizal fungi (AMF) communities isolated from different test plots subjected to long-term fertilisation on soil enzyme activities, number of soil bacteria and fungi. The results showed that the inoculation of arbuscular mycorrhizal fungi communities increased the mycorrhizal infection rate of the plants and promoted the growth of plants. The Mnp treatment was most effective. The shoot biomass, root biomass, potassium and nitrogen uptake of the white clover in Mnp treatment group were increased by 61.54%, 84.00%, 62.50% and 46.71% respectively, compared with those in non-inoculation treatment. The inoculation of AMF communities had little effect on the number of bacteria in the soil, but significantly increased the number of soil fungi. Mnk treatment group had the highest number of fungi in the soil, which was 9.91 times that of the non-inoculation treatment group. The catalase and dehydrogenase activities were both significantly improved in Mnp treatment by 28.12% and 205.38% respectively, compared with those of the control treatment (-M). The urease, invertase and cellulase activities reached the highest levels in the Mck treatment; they were increased by 142.79%, 41.17% and 77.62% respectively, compared with those of the control treatment. Pearson correlation analysis showed that the soil enzyme activity was not correlated with the mycorrhizal infection rate, but correlated with the spore number of the AMF community. The impact of AMF community on soil quality is important for us to understand the function of the ecosystems. Relevant study provides important guidance for maintaining the balance of the soil-plant system and the development of sustainable agriculture.     

城镇污水处理厂进出水对日本青鱂早期阶段亚慢性毒性效应

采用日本青鳉胚胎及幼鱼暴露评估污水处理厂进出水的综合毒性效应。水样采自广州市3个污水处理厂的进水口和出水口。96 h青鳉幼鱼急性毒性试验表明:6个水样均没有对青鳉幼鱼产生急性毒性效应。14 d胚胎暴露试验结果:3个污水处理厂的进水及1号和3号污水处理厂的出水均引起胚胎死亡,胚胎孵化率均低于70%且均与对照组产生了显著性差异(p0.05)。3个厂的进水和1号、2号厂出水的鱼苗畸形率与对照组也有显著差异(p0.05),其中3号厂进水鱼苗畸形率高达(33.73±8.94)%。而6个水样的胚胎孵化时间均与对照组无显著差异(p0.05),均在9 d左右。7 d鱼苗暴露试验结果:1、2、3号3个水厂进水的鱼苗死亡率分别是(30.16±2.75)%,(24.07±1.60)%,(37.90±4.77)%,与对照组产生明显差异(p0.05)。出水对鱼苗的致死效应明显低于进水,但出水对鱼苗的致死效应相对于对照组仍有显著差异(p0.05)。     

Comparative Toxicity of Copper and Zinc to Isolated Eel Hepatocytes

Attempts were made to elucidate lethal responses of hepatocytes of Japanese eel (Anguilla japonica) exposed to Krebs-HEPES buffer at different concentrations of Cu⁺⁺ and Zn⁺⁺. It was found that the 2-hr LC₅₀ value of Cu⁺⁺ and Zn⁺⁺ on eel hepatocytes was 490 and 1576 μM for Cu⁺⁺ and Zn⁺⁺ in single solution, and 1734 and 5200 μM in mixed solution. the toxic effects of Cu⁺⁺ and Zn⁺⁺ on eel hepatocytes were characteristic of antagonistic interaction. After 2-hr exposure, the amount of accumulated metal on the hepatocytes and the mortality of hepatocytes were increased with increasing metal concentration in Krebs-HEPES buffer. the accumulated amount of both metals was significantly decreased when the eel hepatocytes were exposed to mixed metals than to single metal.     

日本《废弃物处理法》对我国城市生活垃圾分类立法的启示

住房和城乡建设部发布《生活垃圾分类标志》新标准,城市生活垃圾分类工作逐步推进,但是仍然存在尚待完善之处。日本《废弃物处理法》是日本生活垃圾分类治理的立法依据,其成功经验颇值得借鉴。在总结《日本废弃物处理法》的立法概况和分析其城市生活垃圾分类立法特征的基础上,探讨我国城市生活垃圾分类立法现状,从立法目的与原则、城市生活垃圾分类标准、各主体的法律责任及惩罚措施4个维度提出具体优化路径。     

锌污染条件下VA菌根对三叶草生长和元素吸收的影响

采用三室隔网盆栽方法研究了3种不同施锌水平下，接种VA菌根菌（G.mosseae）对红三叶草植株生长和养分吸收的影响．结果表明，施锌水平对菌根侵染率无显著影响，说明供试菌种对锌的污染有较强的适应能力．菌根的浸染显著改善了植物的磷营养状况，使植株含磷量增加了1倍多，因此大大促进了植株的生长．菌根侵染对微量元素表现出不同的作用，与不接种的对照相比，菌根侵染植株体内Cu的含量增加，Fe的含量降低，而对Zn、Mn的影响不大．