Sequestration of plant secondary compounds by butterflies and moths

Summary A number of aposematic butterfly and moth species sequester toxic substances from their host plants. Some of these insects can detect the toxic compounds during food assessment. Some pipevine swallowtails use aristolochic acids among the host finding cues during oviposition and larval feeding and accumulate the toxins in the body tissues throughout all life stages. Likewise, a danaine butterfly,Idea leuconoe, which sequesters high concentrations of pyrrolizidine alkaloids in the body, lays eggs in response to the specific alkaloid components contained in the apocynad host. Insect species sharing the same poisonous host plants may differ in the degree of sequestration of toxins. Two closely ralated aposematic geometrid moth species,Arichanna gaschkevitchii andA. melanaria, sequester a series of highly toxic diterpenoids (grayanotoxins) in different degrees, while a cryptic geometrid species,Biston robstus, does not sequester the toxins, illustrating the diversity in adaptation mechanisms even within the same subfamily. By contrast, a number of lepidopteran species store the same compounds though feeding upon taxonomically diverse plant species. A bitter cyanoglycoside, sarmentosin, was characterised from several moth species in the Geometridae, Zygaenidae and Yponomeutidae, and from the apollo butterflies,Parnassius spp. (Papilionidae), although each species feeds on different groups of plants.Interspecific similarities and differences in life history and ecology are discussed in relation to variable characteristics of sequestration of plant compounds among these lepidopteran insects.     

Parasitic wasps orient to green leaf volatiles

Summary Undamaged plants emit low levels of green leaf volatiles (GLVs), while caterpillar-damaged and artificially damaged plants emit relatively higher levels of certain GLVs. Female braconid parasitoids,Microplitis croceipes, oriented to both damaged plants and to individual GLVs in no-choice tests in a wind tunnel, but seldom oriented to undamaged plants. Female ichneumonid parasitoids,Netelia heroica, also oriented to individual GLVs in a wind tunnel. Males of both wasp species failed to orient to the GLVs. These data show that leaf-feeding caterpillars can cause the release of GLVs, and that parasitic wasps can respond to these odors by flying upwind (chemoanemotactic response), which brings the wasps to their caterpillar hosts. This supports the hypothesis that plants communicate with members of the third trophic level,i.e., plants under herbivore attack emit chemical signals that guide natural enemies of herbivores to sites of plant damage. In this interaction, the GLVs serve as tritrophic plant-to-parasitoid synomones. That parasitoids from two different wasp families oriented to GLVs suggests that the response may be widespread among the Hymenoptera.Mention of a commercial or proprietary product does not constitute an endorsement by the U.S. Department of Agriculture     

Indicators for Chemicals: Sources,impacts and policy performance (5 pp)

Background Different types of indicators have been developed to describe the impact of chemicals on society and environment. Due to the high number of substances and their different types of use, most of these indicators are directed to specific areas of interest – regarding workplace safety, environmental health or consumer health. They address a specific subset of chemicals and can be used for monitoring enterprise-specific, national or international management measures. Main Features A survey of existing indicators for chemicals has shown that indicators already exist for a remarkable number of problem fields. As soon as the release and the environmental fate of chemicals are taken into account, the complexity of the approaches increases considerably. The distinction between indicators for drivers, pressures, state, impacts and responses, as proposed by the European Environmental Agency, supports the identification of proper indicators for a specific type of problem. Discussion and Conclusions. No single indicator exists which is able to cover the whole range of chemicals and their applications. Several indicator approaches cover at least a subset of the most relevant substances. If they are intended to be used for European monitoring, robust data must be provided by EU Member States. Chemicals in enterprises (ancillary inputs as well as process chemicals) are an important element of in-plant material flow management – in terms of occupational safety and health as well as environmental protection. Existing indicators for hazardous chemicals can be a valuable tool for process and product refinement regarding hazardous chemicals, especially for enterprises. Outlook Indicators for production and impact of chemicals, as well as policy performance indicators, are essential elements in order to monitor the management of chemicals. They have to be established for the national and for the EU level.     

嫌气条件下土壤中有机还原性物质的动态变化

利用示差脉冲伏安法研究了不同有机物料在嫌气培养条件下产生的有机还原性物质的动态变化．结果表明：在培养起始阶段，强还原性有机物质的数量迅速增加，以后逐渐下降．不同有机物料所产生的有机还原性物质的强度和数量各不相同。培养初期，有机还原性物质种类较多，长时间培养后，部分还原能力较弱的有机物质消失。长时间培养后。嫌气培养液中强还原性有机物质可能与金属离子作用，使其活性降低。     

Influence of humic fractions on retention of isoproturon residues in two Moroccan soils

The influence of different fractions of soil organic matter on the retention of the herbicide isoproturon (IPU) has been evaluated. Water and methanol extractable residues of ¹⁴C labeled isoproturon have been determined in two Moroccan soils by β -counting–liquid chromatography. The quantification of bound residues in soil and in different fractions of soil humic substances has been performed using pyrolysis/scintillation-detected gas-chromatography. Microbial mineralization of the herbicide and soil organic matter has been also monitored. Retention of isoproturon residues after 30-days incubation ranged from 22% to 32% (non-extractable fraction). The radioactivity extracted in an aqueous environment was from 20% to 33% of the amount used for the treatment; meanwhile, methanol was able to extract another 48%. Both soils showed quantities of bound residues into the humin fraction higher than humic and fulvic acids. The total amount of residues retained into the organic matter of the soils was about 65 % of non-extractable fraction, and this percentage did not change with incubation time; on the contrary, the sorption rate of the retention reaction is mostly influenced by the clay fraction and organic content of the soil. Only a little part of the herbicide was mineralized during the experimental time.     

消除身边隐患 保障健康安全——国内外玩具安全标准与法规介绍

本文主要介绍了ISO8124《玩具安全》系列标准、美国玩具安全标准和法案、欧盟玩具安全标准和指令以及我国的玩具安全标准GB24613-2009制定背景、适用范围、有害物质限量等,同时还就玩具安全标准未来发展提出了建议。     

缸内直喷汽油车颗粒物化学组分特征

随着缸内直喷汽油车（GDI）的大量使用,其尾气颗粒物排放问题日益凸显.研究缸内直喷汽油车尾气颗粒物构成组分是有效控制其颗粒物排放的重要前期工作之一.选取了5辆满足国六排放标准的缸内直喷汽油车进行了尾气颗粒物碳质成分、水溶性离子和多环芳烃（PAHs）组分分析.结果发现,各类碳质是测试车辆尾气颗粒物中的主要成分,平均占比约70%.颗粒物碳质中有机碳质（OC）多于核态碳质（EC）,OC/EC比值在1.03~3.43之间.测量了颗粒物中多种水溶性离子的含量,结果表明Ca²⁺和SO₄^2-是尾气颗粒物中的主要水溶性离子,主要来源均为机油添加剂.此外,结果还发现GDI车辆尾气颗粒物中高环PAHs排放占比较高,对人体健康危害大,需要重点关注.     

Modeling the binding of triazine herbicides to humic substances using capillary electrophoresis

The binding of 4 s-triazines herbicides and metabolites, ameline, hydroxyatrazine, atraton, and ametryn to 12 structurally different humic substances was studied by affinity capillary electrophoresis. Binding data were confronted to the structural data of humic acids obtained from spectrometric measurements (UV-Vis, FT/IR, NMR), elemental analysis and potentiometric titration. The results obtained with principal component analysis and partial least square analysis clearly show the importance of carboxylic acidity and aromaticity of the humic ligands in relation to the partial positive charge and relative hydrophobicity of the pesticides.     

生物沥浸处理中微生物菌群和胞外聚合物对城市污泥脱水性能的影响

探讨城市污泥生物沥浸过程中微生物菌群和胞外聚合物(EPS)变化对污泥脱水性能的影响,对进一步揭示生物沥浸法提高污泥脱水性能机理具有重要意义.本研究通过摇瓶试验探讨了硫杆菌和异养微生物菌群数量的变化及EPS在生物沥浸法提高城市污泥脱水性能中的作用.试验结果表明,在生物沥浸处理的前2 d内,由于硫杆菌A.ferrooxidans LX5和A.thiooxidans TS6的大量生长,导致生物沥浸污泥的pH从初始的4.62显著下降至2.47,进而导致污泥中异养菌数量从初始的2.65×108CFU·mL-1下降至8.20×106CFU·mL-1,污泥中EPS含量从初始的28.18 mg·g-1(以VSS计,下同)显著下降为13.53 mg·g-1.A.ferrooxidans LX5和A.thiooxidans TS6的大量生长、异养微生物细胞的死亡破裂及EPS含量的下降共同促使污泥的结合水含量从初始的37.28%下降至21.10%,最终导致污泥比阻从初始的5.14×1012m·kg-1显著下降至6.92×1011m·kg-1.通过验证试验发现,原始污泥在剥离EPS后其比阻仅为原来的11.23%,其脱水性能与生物沥浸2 d后的污泥在0.05水平上没有显著性差异.因此,污泥中A.ferrooxidans LX5、A.thiooxidans TS6和异养微生物菌群数量的改变及EPS含量的减少是生物沥浸法提高污泥脱水性能的两个重要因素.     

Extraction and characterization of bound extracellular polymeric substances from cultured pure cyanobacterium (Microcystis wesenbergii)

Preliminary characterization of bound extracellular polymeric substances（bEPS） of cyanobacteria is crucial to obtain a better understanding of the formation mechanism of cyanobacterial bloom. However,the characterization of bEPS can be affected by extraction methods. Five sets（including the control） of bEPS from Microcystis extracted by different methods were characterized using three-dimensional excitation and emission matrix（3DEEM） fluorescence spectroscopy combined chemical spectrophotometry; and the characterization results of bEPS samples were further compared. The agents used for extraction were NaOH,pure water and phosphate buffered saline（PBS） containing cationic exchange resins,and hot water. Extraction methods affected the fluorescence signals and intensities in the bEPS. Five fluorescence peaks were observed in the excitation and emission matrix fluorescence spectra of bEPS samples. Two peaks（peaks T1 and T2） present in all extractions were identified as protein-like fluorophores,two（peaks A and C） as humic-like fluorophores,and one（peak E） as a fulvic-like substance.Among these substances,the humic-like and fulvic-like fluorescences were only seen in the bEPS extracted with hot water. Also,NaOH solution extraction could result in strong fluorescence intensities compared to the other extraction methods. It was suggested that NaOH at pH 10.0 was the most appropriate method to extract bEPS from Microcystis. In addition,dialysis could affect the yields and characteristics of extracted bEPS during the determination process. These results will help us to explore the issues of cyanobacterial blooms.