Biochemical studies on the terrestrial snail,Eubania vermiculata (müller)treated with some pesticides

Abstract

The in vivo effects of methomyl, thiodicarb and metaldehyde on total soluble proteins, total lipids and glycogen content, in addition, the activity of glutamic oxaloacetic transaminase, (GOT), (GPT) glutamic pyruvic transaminase and catalase (CAT) enzymes of terrestrial E. vermiculata snails was studied. The experimental snails were treated with low concentration of 0.2% bran bait w/w of the pesticides for a period of 1,3,5,7 and 10 days. The results showed that methomyl and thiodicarb lead to significant reduction in total soluble proteins, lipids, and glycogen content, while significant increases in the activity of all enzymes tested were noted. Metaldehyde treatment showed no significant effect on total soluble proteins, lipids and GOT level, whereas a significant increase in GPT and CAT enzymes was observed. Also, metaldehyde resulted a significant reduction in glycogen content of snails.     

Conservation Biology, Genetically Modified Organisms, and the Biosafety Protocol

Abstract:  Concerns have been raised regarding the potential adverse effects on biological diversity of the use of living modified organisms (LMOs, which are commonly known by similar terms such as genetically modified organisms). At the international level these concerns are addressed in part by an agreement known as the Cartagena Protocol on Biosafety and include potential toxic effects of insect-resistant crops on nontarget organisms and potential ecological effects of gene flow from modified crops, fish, microorganisms, or insects to wild species or counterparts. We reviewed the protocol's main provisions, including those dealing with risk assessment and risk management, decision making on imports, documentation accompanying shipments, and liability resulting from damages caused by LMOs. A medium-term program of work has been adopted by the parties, which includes the potential contribution of conservation biologists to delivering capacity building, developing risk assessment guidance, evaluating mechanisms of potential ecological damages from LMOs, and other issues. Conservation biologists and other experts have opportunities to influence the negotiations and implementation of the protocol by providing inputs at meetings, offering expertise to governments and organizations, and participating in or developing relevant projects and initiatives. Involvement of conservation biologists in the implementation and further development of the protocol would contribute to its effectiveness.     

冲击负荷对厌氧序批式反应器的影响及其恢复重建过程

研究了在厌氧条件下以葡萄糖为基质的厌氧序批式反应器(ASBR)中冲击负荷对基质吸收和储存的影响及其恢复重建过程.结果表明,正常状态下,反应器在进水COD为5 000.0 mg/L,出水COD为188.6 mg/L,当进水负荷提高至正常状态2倍后,反应器中COD大量累积,其中51.13％为挥发性有机酸(VFA),48.87％则被转化为糖原储存在细胞体内,出水COD最高为2 368.9 mg/L,污泥糖原储存量最高为273.55 mg/g(以挥发性固体计),是正常状态的4.2倍.在冲击负荷条件下,反应器的产甲烷能力恢复较快,胞内糖原储存恢复较慢,出水COD和胞内糖原分别经过20、41 d后恢复冲击负荷前水平.     

Novel Organisms: Comparing Invasive Species, GMOs, and Emerging Pathogens

Invasive species, range-expanding species, genetically modified organisms (GMOs), synthetic organisms, and emerging pathogens increasingly affect the human environment. We propose a framework that allows comparison of consecutive stages that such novel organisms go through. The framework provides a common terminology for novel organisms, facilitating knowledge exchange among researchers, managers, and policy makers that work on, or have to make effective decisions about, novel organisms. The framework also indicates that knowledge about the causes and consequences of stage transitions for the better studied novel organisms, such as invasive species, can be transferred to more poorly studied ones, such as GMOs and emerging pathogens. Finally, the framework advances understanding of how climate change can affect the establishment, spread, and impacts of novel organisms, and how biodiversity affects, and is affected by, novel organisms.     

Heavy Metal Concentrations in Water, Sediment, Fish and Some Benthic Organisms from Tigris River, Turkey

In this study concentrations of heavy metals, such as Cd, Co, Cu, Fe, Mn, Ni, Pb and Zn were determined in water, sediment, muscle, liver and gill of fish (Silurus triostegus, Mastacembelus simack, Mystus halepensis, Orthrias euphraticus) the muscle and liver of crab (Potamon fluviatilis), the internal organs of fresh water snail (Physa acuta), and mussel (Unio elongatulus), and in whole biomass of green algae (Spirogyra sp.) examples collected seasonally from three selected sites (I, II, and III) of Tigris River and from a reference site on Resan Creek. In general, the average Cd, Cu, Mn, Ni, Zn, and Fe values in Sites I, II, and III were found to be high in spring and summer. The concentrations of heavy metals in the Tigris River are compared with previous studies in the same sites. The results showed that Cu levels have gradually decreased during recent years. In Tigris River, among the living organisms, i.e., those which are living in benthic region and showing biomonitor characteristic, crab, snail, green algae, mussel and fish are seen to be formed in sequence. Cu, Fe, Mn and Zn values obtained from the muscle of fish and from the mass of internal organs of mussel and snail were found to be under the acceptable values suggested.     

高分子吸水树脂作为蓄冷材料的性能研究

本文研究了不同吸水倍率的高分子吸水树脂的相变温度、相变潜热及作为蓄冷材料在35℃环境下的相变时间,并与冰做了对比。结果显示：吸收不同倍率水的高分子树脂。相变温度和相变潜热基本与水相似,随着吸水倍率的增加,相变潜热越接近于水的潜热;在相同条件下放置于隔冷袋中的高分子吸水树脂．在35℃高温环境中,可以维持20℃以下低温5h,比冰多了将近1h,克服了渗漏的缺点,在蓄冷领域表现出了明显的优势。     

超高压工程电缆绝缘油对海洋生物的生态毒性效应

随着超高压联网工程建设项目不断增多,取得巨大经济效益的同时,其电缆安全性日益受到关注。采用标准实验方法,研究电缆绝缘油对8种占据不同生态位的海洋生物(费氏弧菌(Vibrio fischeri)、牟氏角毛藻(Chaetoceros mueleri)、卤虫(Artemia sp.)、蒙古裸腹溞(Moina mongolica)、凡纳滨对虾(Litopenaeus vannamei)、裸项栉鰕虎鱼(Ctenogobius gymnauchen)、双齿围沙蚕(Perinereis aibuhitensis)、菲律宾蛤仔(Ruditapes philippinarum))的急性毒性,同时进行了电缆绝缘油对裸项栉鰕虎鱼14 d延长毒性实验和电缆绝缘油对蒙古裸腹溞的慢性毒性。结果表明,电缆绝缘油在50%饱和溶解浓度下未对费氏弧菌产生明显的发光抑制作用;对牟氏角毛藻、凡纳滨对虾、裸项栉鰕虎鱼、双齿围沙蚕和菲律宾蛤仔等5种生物未表现出急性毒性影响,其LC50均大于饱和浓度;对卤虫的96 h-LC50为17.07%,LOEC为12.5%,NOEC为6.25%;对蒙古裸腹溞96 h-LC50为29.75%,LOEC为25.0%,NOEC为12.5%;电缆绝缘油对卤虫和蒙古裸腹溞有剧毒。对裸项栉鰕虎鱼成鱼14 d延长毒性LC50大于500 000 mg·L~(-1);对蒙古裸腹溞母溞存活数的NOEC为625μg·L~(-1),LOEC为1 250μg·L~(-1);对母溞存活期的NOEC为312μg·L~(-1),LOEC为625μg·L~(-1);对产胎数的NOEC为625μg·L~(-1),LOEC为1 250μg·L~(-1);对产幼溞数的NOEC为625μg·L~(-1),LOEC为1 250μg·L~(-1)。     

Simulation of long-term nutrient removal in a full-scale closed-loop bioreactor for sewage treatment: an example of Bayesian inference

In this study, the performance of nitrogen and phosphorus removal in a full-scale closed-loop bioreactor (oxidation ditch) system was simulated using the ASM2d model. Routine data describing the process for two years were compiled for calibration and validation. To overcome the identifiability problem, the classic Bayesian inference approach was utilized for parameter estimation. The calibrated model could describe the long-term trend of nutrient removal and short-term variations of the process performance, showing that the Bayesian method was a reliable and useful tool for the parameter estimation of the activated sludge models. The anoxic phosphate uptake by polyphosphate accumulating organisms (PAO) contributed 71.2% of the total Poly-P storage, which reveals the dominance of denitrifying phosphorus removal process under the oxygen limiting conditions. It was found that 58.7% of the anoxic Poly-P storage and denitrification by PAO in the reactor was achieved in the aerated compartment, implying that the PAO’s anoxic activity was significantly stimulated by the low dissolved oxygen (DO) level in this compartment due to the oxygen gradient caused by brush aerator.     

反硝化颗粒污泥在纳米零价铁胁迫下的性能恢复

为探明纳米零价铁(nZVI)对反硝化颗粒污泥(DGS)潜在的胁迫效应,本研究通过连续多批次实验,考察了经历n ZVI短期冲击后,DGS反硝化活性在不同C/N比条件下的恢复情况.结果表明,当nZVI投加量高于5 mg·L~(-1)时,DGS比反硝化速率(μ)会出现下降,对应的比反硝化抑制率(IR)与基质C/N比、nZVI投加量呈现正相关.当nZVI投加量达到100 mg·L~(-1)时,胞外蛋白与多糖含量均明显降低.此时,充足的外加碳源(C/N≥4)将有助于促进DGS反硝化活性的恢复和减少去除单位硝态氮所消耗的COD值.由Freundlich和Langmuir吸附等温线的拟合结果可知,基质C/N比越高,DGS对n ZVI的吸附能力就越强.在恢复期内,泥相中总铁含量(Qe)的持续削减为高C/N比条件下,DGS反硝化活性的提升创造了有利条件.当Qe降至0.4 mg·g~(-1)以下时,μ值可达到或接近对照组的水平.     

集约化蔬菜种植区地下水中反硝化细菌的分离鉴定

从研究我国典型集约化蔬菜种植区地下水中硝酸盐的来源和浓度人手,进行富集、培养、分离、纯化,筛选出一株具有反硝化作用的菌株,通过形态学、革兰氏染色结合16SrDNA序列同源性分析鉴定,其鉴定结果为农杆菌(Agrobacterium sp.).该研究为开展地下水硝酸盐污染的生物修复储备宝贵的菌种资源,为地下水中硝酸盐污染的原位微生物修复和相关污水的生物处理提供微牛物基础,对于经济、有效的解决地下水硝酸盐污染和水资源短缺的问题有着十分重要的意义.