Cd2+对角突臂尾轮虫和曲腿龟甲轮虫的急性毒性和生命表统计学参数的影响

采用急性毒性试验研究了(25±1)℃下Cd²⁺对角突臂尾轮虫(Brachionus angularis)和曲腿龟甲轮虫(Keratella valga)的24 h LC₅₀值, 采用生命表实验方法研究了(25±1)℃下、以密度为1.0×10⁶ 个细胞/mL的斜生栅藻为轮虫食物时不同浓度(7.0、12.0、20.4、34.6、58.8,100.0 μg/L)的Cd²⁺对角突臂尾轮虫和曲腿龟甲轮虫生命表统计学参数的影响。结果表明, Cd²⁺对角突臂尾轮虫和曲腿龟甲轮虫幼体的24 h LC₅₀值分别为95.5 μg/L和231.9 μg/L。Cd²⁺浓度对角突臂尾轮虫的种群内禀增长率具有显著的影响(P<0.05), 对曲腿龟甲轮虫的世代时间、生命期望和净生殖率具有显著的影响(P<0.05)。与对照组相比, 100.0 μg/L的Cd²⁺显著降低了角突臂尾轮虫的种群内禀增长率; 34.6 μg/L和58.8 μg/L的Cd²⁺显著降低了曲腿龟甲轮虫的世代时间, 34.6和100.0 μg/L的Cd²⁺显著降低了曲腿龟甲轮虫的生命期望, 34.6 μg/L的Cd²⁺显著降低了曲腿龟甲轮虫的净生殖率。角突臂尾轮虫对Cd²⁺污染的敏感性较曲腿龟甲轮虫强, 各生命表统计学参数对污染物的敏感性因轮虫种类的不同而异。     

四种类型杀虫剂对麦长管蚜的温度效应及其与主要解毒酶的关系

为了明确杀虫剂毒力受温度的影响及其程度,本文测定了4大类8种药剂在10～25℃下对麦长管蚜的毒力;并测定了麦长管蚜Sitobion avenae(Fabricius)在不同温度下2个解毒酶和1个靶标酶的活性差异。结果表明,高效氯氰菊酯对麦长管蚜表现不规则负温度系数,啶虫脒表现不规则正温度系数,高效氟氯氰菊酯对麦长管蚜的毒力不受温度影响,其他药剂(辛硫磷、毒死蜱、灭多威、丁硫克百威、吡虫啉)均表现为明显的正温度系数效应,以有机磷类杀虫剂表现最为明显,毒死蜱温度系数高达57.70。酶活性实验表明:麦长管蚜在高温下GST活性增强,羧酸酯酶和乙酰胆碱酯酶活性降低。它们的变化规律表明:GST活性与负温度系数密切相关,正温度系数与羧酸酯酶活性和靶标酶乙酰胆碱酯酶活性有关。     

赤拟谷盗的磷化氢敏感和抗性品系体内羧酸酯酶的活性比较

本文比较测定了赤拟谷盗Tribolium castaneum(Herbst)的磷化氢抗性(Rf=327)和敏感品系害虫的羧酸酯酶活性,研究了该害虫同一品系不同个体间羧酸酯酶的活性差异,比较了两品系害虫在系列磷化氢浓度下熏蒸24h和6.94×10-2mg/L磷化氢浓度下熏蒸不同时间的羧酸酯酶活性。主要结果为:未熏蒸的抗性害虫幼虫和蛹体内的羧酸酯酶活性分别高于敏感品系的1.37和1.16倍;敏感和抗性害虫同品系内不同个体间羧酸酯酶活性分布频率都存在明显差异,抗性害虫中酶活性大的个体数量占的比例较大;磷化氢浓度分别为0.69×10-2、2.78×10-2、5.56×10-2、8.33×10-2和11.11×10-2mg/L时都可导致敏感害虫羧酸酯酶的活性降低,但活性受抑制的程度不因浓度高低呈相应的增减。浓度分别为5.56×10-2、11.11×10-2、13.89×10-2、20.83×10-2和27.78×10-2mg/L的熏蒸中抗性害虫体内酶活性增加,且活性增高的程度与浓度增减也不呈对应变化。在6.94×10-2mg/L磷化氢浓度下熏蒸不同时间的结果中,敏感害虫的酶活性随时间延长而下降,抗性害虫的活性则随时间延长而增大。研究表明赤拟谷盗对磷化氢的抗性可能与羧酸酯酶的活性增加有关。     

毒死蜱对不同温度下饲养的小菜蛾幼虫羧酸酯酶的抑制作用

毒死蜱对不同温度下饲养的小菜蛾3龄幼虫羧酸酯酶的体内抑制动态规律有明显的差异.饲养于不同温度下的小菜蛾幼虫羧酸酯酶活性在受到毒死蜱的抑制之后,其恢复速度不同,其中饲养于30℃的小菜蛾3龄幼虫羧酸酯酶活性恢复最快,饲养于20℃的次之,饲养于10℃的恢复最慢.     

双酚A对萼花臂尾轮虫毒性及生活史的影响

应用生态毒理学研究方法,研究了双酚A(BPA)对萼花臂尾轮虫毒性及生活史影响。结果表明:BPA对萼花臂尾轮虫24 h急性毒性LC₅₀为13.76 mg/L,95%置信限为10.97-17.10 mg/L。生活史研究显示:与对照组相比,0.25-4.0 mg/L的BPA对轮虫胚胎发育历时影响不显著;2.0-4.0 mg/L的BPA显著延迟了轮虫幼体发育时间;当BPA为0.5 mg/L时,轮虫净生殖率(R₀)显著上升,但BPA浓度为2.0和4.0 mg/L时R₀显著降低;4.0 mg/L的BPA显著缩短世代时间(T);BPA浓度为2.0、4.0 mg/L时,轮虫生命期望值(e₀)显著下降;BPA浓度为1.0、2.0、4.0 mg/L时,轮虫内禀增长率(r_m)显著下降;BPA浓度为0.5、1.0 mg/L时轮虫所产后代混交率(MR)显著增长。研究结果表明BPA对轮虫的生殖具有干扰作用,其中R₀和MR受BPA影响最为显著。     

四种农药对小菜蛾体温的影响

【目的】本研究旨在为阐明小菜蛾Plutellaxylostella体温在其防治中的应用价值提供资料。【方法】在不同人工气候箱内温度(环境温度)下,测定小菜蛾2, 3和4龄幼虫的体温,建立各龄幼虫体温(y)与环境温度(x)的关系方程;同时测定了不同环境温度下不同浓度阿维菌素、毒死蜱、氟虫腈和高效氯氰菊酯分别处理后小菜蛾3龄幼虫在不同处理时间的体温。【结果】小菜蛾2, 3和 4龄幼虫体温(y)与环境温度(x)关系方程分别为y＝0.95x+1.19(r=0.9463), y＝0.95x+1.18(r=0.9988),以及y＝0.93x+1.45(r=0.9989),等温点分别为22.16℃,21.40℃和21.41℃。在气候箱温度设定为15℃或40℃时,4种农药都对小菜蛾3龄幼虫体温无影响;而其他温度条件下,农药处理都可能改变小菜蛾3龄幼虫体温。对于阿维菌素,25℃下 2, 4和8 mg/L处理12 h,2和4 mg/L处理24 h, 0.5, 2, 4和8 mg/L处理36 h以及0.5, 1, 2和8 mg/L处理48 h时3龄幼虫体温均显著高于对照, 8 mg/L阿维菌素处理24 h时3龄幼虫体温显著低于对照;30℃下0.5 mg/L处理24 h及1 mg/L处理36 h 3龄幼虫体温显著低于对照,1 mg/L处理48 h和各浓度处理60 h时3龄幼虫体温均显著高于对照;35℃下只有1和8 mg/L处理48 h时3龄幼虫体温显著低于对照。对于毒死蜱,20℃下50, 200和800 mg/L处理24 h, 100, 400和800 mg/L处理36 h时3龄幼虫体温都显著低于对照;25℃下100和200 mg/L处理12h, 800 mg/L处理24 h, 100, 200和800 mg/L处理60 h时3龄幼虫体温均显著低于对照,而50, 100, 200和400 mg/L处理24 h, 100和200 mg/L处理36 h及100和400 mg/L处理48 h时3龄幼虫体温均显著高于对照;30℃下只有800 mg/L处理24 h时3龄幼虫体温显著低于对照,50, 100, 200和800 mg/L处理60 h时3龄幼虫体温显著高于对照。对于氟虫腈,20℃下只有0.5 mg/L处理36 h时3龄幼虫体温显著低于对照;25℃下 4 mg/L处理12 h和各浓度处理60 h时3龄幼虫体温显著低于对照,0.5 mg/L处理24 h以及0.25, 1和2mg/L处理48 h时3龄幼虫体温均显著高于对照;30℃下 0.25和0.5 mg/L处理12 h, 0.25和2 mg/L处理24h, 4 mg/L处理48 h以及2 mg/L处理60 h时3龄幼虫体温显著低于对照;35℃下只有0.25和0.5 mg/L处理60 h时3龄幼虫体温显著高于对照。对于高效氯氰菊酯,20℃下2和8 g/L处理36 h, 4和8 g/L处理48 h时3龄幼虫体温显著高于对照;25℃下 2, 4和8 g/L处理12 h时3龄幼虫体温均显著低于对照, 0.5, 4和8g/L处理24 h, 1, 4和 8 g/L处理36 h以及1, 2和4 g/L处理60 h时3龄幼虫体温均显著高于对照;30℃下 0.5和1 g/L浓度处理12 h, 0.5, 1, 4和8 g/L处理24 h以及1, 2和8 g/L处理60 h时3龄幼虫体温都显著低于对照。【结论】小菜蛾幼虫自律性体温调节能力低;阿维菌素、毒死蜱、氟虫腈或高效氯氰菊酯处理影响小菜蛾3龄幼虫的体温,影响形式随农药种类和浓度,环境温度及处理时间不同而不同。本研究拓宽了农药毒理学及害虫防治研究内容。     

运用α-氰代酯荧光底物检测抗性棉蚜羧酸酯酶代谢活性

为了研究抗性和敏感棉蚜Aphis gossypii品系对菊酯类药剂代谢的差异, 本实验合成了溴氰菊酯和高效氯氰菊酯报告荧光底物, 应用这两种底物水解后生成具有荧光化合物的特性,测定了不同品系棉蚜羧酸酯酶的代谢活性。结果表明: 氧化乐果棉蚜抗性和敏感品系羧酸酯酶对溴氰菊酯报告荧光底物的代谢活性分别为10.0和3.4 pmol/min·mg; 对高效氯氰菊酯报告荧光底物的代谢活性分别为4.0和2.4 pmol/min·mg, 抗性品系羧酸酯酶对溴氰菊酯和高效氯氰菊酯报告荧光底物的代谢活性分别为敏感品系的2.9和1.7倍; 溴氰菊酯棉蚜抗性和敏感品系羧酸酯酶对溴氰菊酯报告荧光底物的代谢活性分别为7.6和6.2 pmol/min·mg; 对高效氯氰菊酯报告荧光底物的代谢活性分别为9.3和5.2 pmol/min·mg, 抗性品系羧酸酯酶对溴氰菊酯和高效氯氰菊酯报告荧光底物的代谢活性分别为敏感品系的1.2和1.8倍。这种衍生的报告荧光底物能够用来检测抗性棉蚜羧酸酯酶的水解活性, 表明羧酸酯酶可能参与棉蚜对溴氰菊酯和氧化乐果抗性的形成。     

不同温度及二氧化碳浓度下培养的龙须菜光合生理特性对阳光紫外辐射的响应

为了研究不同温度及CO₂浓度下培养的大型海藻对紫外辐射的生理学响应,选取龙须菜(Gracilaria lemaneiformis)作为实验材料。实验设置两个温度梯度(20 ℃和24 ℃),两种CO₂浓度(390 μL/L和1000 μL/L)以及3种辐射处理,即可见光(PAR)处理(滤除紫外线A(UV-A)、紫外线B(UV-B),400-700 nm)、可见光加紫外线A(PA)处理(滤除UV-B,320-700 nm)、PAB处理(全波长辐射280-700 nm)。结果表明,酸化、升温以及紫外辐射处理都未影响大型经济红藻龙须菜的叶绿素a和类胡萝卜素的含量。然而紫外辐射处理显著降低了龙须菜的有效光化学效率,其抑制水平在酸化处理的藻体中更为显著,并且随着温度的上升而进一步加剧;酸化与温度耦合使藻体对紫外辐射的敏感性增加,导致其较低的修复速率以及较高的损伤速率。     

红裸须摇蚊幼虫生物标志物系统对苯酚的响应

以红裸须摇蚊4龄幼虫为对象,测定了苯酚对摇蚊幼虫急性毒性、体质量、化蛹率及体内保护酶和解毒酶活性的影响.结果表明:苯酚对摇蚊4龄幼虫6、24、48、72和96 h半致死浓度LC50分别为222.52、134.86、67.74、47.39和35.76 mg.L-1;亚致死剂量苯酚(0.4、4和40 mg.L-1)处理降低摇蚊4龄幼虫干湿质量和化蛹率;摇蚊4龄幼虫暴露于苯酚液72 h,过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、谷胱甘肽S转-移酶(GST)和羧酸酯酶(CarE)均对苯酚暴露做出响应,且随着浓度增加和暴露时间的延长呈现一定的剂量-时间效应,而摇蚊体内酸性磷酸酯酶(ACP)和碱性磷酸酯酶(ALP)对苯酚暴露响应较迟钝,仅高浓度(40 mg.L-1)长时间(48 h和72 h)的胁迫才会产生显著抑制作用.表明摇蚊体质量、化蛹率和CAT、SOD、GST、CarE可作为监测苯酚水体污染的生物标志物.     

草甘膦对空心莲子草叶甲Agasicles hygrophila成虫3种代谢酶活性的影响

采用不同浓度的草甘膦0.41 g/L、0.82 g/L、1.23 g/L、1.64g/L、2.05 g/L分别以胃毒和触杀法处理空心莲子草叶甲Agasicles hygrophila成虫,测定其乙酰胆碱酯酶(AChE)、羧酸酯酶(CarE)和谷胱甘肽S-转移酶(GSTs)比活力.试验结果表明:两种处理,草甘膦对AChE活力均有不同程度的抑制作用;对CarE活力影响较为显著,在2.05 g/L浓度下,胃毒处理CarE对α-乙酸萘酯(α-NA)和β-乙酸萘酯(β-NA)水解能力分别是对照组的50%和57%,触杀处理CarE对α-乙酸萘酯(α-NA)和β-乙酸荼酯(β-NA)水解能力分别是对照组的53%和59%;胃毒处理埘酶活力影响大于触杀处理,草甘膦对GSTs的活力影响不明显.     

The use of the corticotropin-releasing hormone test to monitor the recovery of patients with Cushing's disease or Cushing's syndrome due to an adrenal adenoma after adenomectomy

Six patients with Cushing's disease and three with Cushing's syndrome due to an adrenal adenoma were monitored after their adenomectomy with the corticotropin-releasing hormone test to evaluate the progress of recovery of their pituitary adrenal function. Before surgery the patients with Cushing's disease showed either high, normal or low responses of plasma ACTH and cortisol to 100 micrograms synthetic ovine corticotropin-releasing hormone (CRH) administered intravenously, whereas all three patients with Cushing's syndrome due to an adrenal adenoma showed no response of plasma ACTH or cortisol to CRH. One or two months after surgery, the patients who had Cushing's disease had low levels of basal plasma ACTH and cortisol and their responses to CRH were extremely low. However, the same patients were tested later, it was found that their responses to CRH gradually increased and reached normal ranges approximately within one year after tumor removal, which coincided with the overall improvement in their clinical signs and symptoms due to adrenal insufficiency. In contrast, the recovery of the pituitary adrenal function in patients who had Cushing's syndrome due to an adrenal adenoma was not complete even one year after surgery. Thus the corticotropin-releasing factor test is a useful criteria to evaluate the recovery of the pituitary adrenal function in these patients after surgery, since the responses of plasma ACTH and cortisol to the administered CRH are parallel with the improvements in clinical signs and symptoms due to adrenal insufficiency in patients with Cushing's disease.     

Serological relationships of the O antigens of Klebsiella pneumoniae O5, Escherichia coli O8 and a new O serotype of Serratia marcescens

Klebsiella pneumoniae O5, Escherichia coli O8 and Serratia marcescens 3255 were shown to cross-react in both ELISA and immunoblotting. The cross-reaction appeared to be due to the O antigen of their lipopolysaccharide (LPS). In addition, there was evidence that the reactions of these strains with their homologous antisera were due, in part, to determinants other than O polysaccharide.     

The adaptive importance of cognitive efficiency: an alternative theory of why we have beliefs and desires

Finding out why we have beliefs and desires is important for a thorough understanding of the nature of our minds (and those of other animals). It is therefore unsurprising that several accounts have been presented that are meant to answer this question. At least in the philosophical literature, the most widely accepted of these are due to Kim Sterelny and Peter Godfrey-Smith, who argue that beliefs and desires evolved due to their enabling us to be behaviourally flexible in a way that reflexes do not—which, they claim, is beneficial in epistemically complex environments. However, as I try to make clear in this paper, upon closer consideration, this kind of account turns out to be theoretically implausible. In the main, this is because it fails to give due credit to the powers of reflex-driven organisms, which can in fact be just as flexible in their behaviour as ones that are belief/desire-driven. In order to improve on this account, I therefore propose that beliefs and desires evolved, not due to their enabling us to do something completely different from what reflexive organisms can do, but rather due to their enabling us to do the same things better. Specifically, I argue that beliefs and desires evolved for making the generation of behaviour more efficient, since they can simplify the necessary cognitive labour considerably. I end by considering various implications of this account.     

A comparative review towards potential of microbial cells for heavy metal removal with emphasis on biosorption and bioaccumulation

The threat of heavy metal pollution to environmental health is getting worldwide attention due to their persistence and non-biodegradable nature. Ineffectiveness of various physicochemical methods due to economical and technical constraints resulted in the search for a cost-effective and eco-friendly biological technique for heavy metal removal from the environment. The two effective biotic methods used are biosorption and bioaccumulation. A comparison between these two processes demonstrated that biosorption is a better heavy metal removal process than bioaccumulation. This is due to the intoxication of heavy metal by inhibiting their entry into the microbial cell. Genes and enzymes related to bioremoval process are also discussed. On comparing the removal rate, bacteria are surpassed by algae and fungi. The aim of this review is to understand the biotic processes and to compare their metal removal efficiency.     

Effects of dopaminergic drugs and acute medial forebrain bundle lesions on striatal acetylcholine levels.

Placement of radio frequency lesions in the medial forebrain bundle resulted in a 50% depletion of striatal acetylcholine levels but did not change hippocampal levels. A similar result was obtained with the administration of chlorpromazine, haloperidol and pimozide. When these drugs were administered simultaneously with placement of lesions, there was the same 50% depletion of striatal acetylcholine. Apomorphine reversed the depletion due to lesions. These results suggest that the action of antipsychotic drugs on the cholinergic system in the striatum is primarily due to their action at dopamine receptors rather than a direct action on cholinergic receptors which would be due to their anticholinergic activity.     

Impact of microbial proteases on biotechnological industries

The demand of enzymes in industrial sectors is increasing rapidly due to their economical and ecological advantages. Micro-organisms produce different types of extracellular enzymes for maintaining their own metabolism, defense, and normal physiological condition. Among several enzymes, proteases have gained special attention in industrial sectors. Several sources of extracellular enzymes are reported by various researchers, but enzymes obtain from microbial sources have high demand in industries due to lower cost, high production rate, availability, stability, and diversity. Among micro-organism, bacteria and fungi are reported to be good sources of different types of proteases such as alkaline protease, cysteine protease, aspartate protease, and metallo protease. In this review, we have summarized the available information about the sources of bacterial and fungal proteases, their purification strategies and their temperature and pH optima. Due to huge competition, companies are trying to reduce their manufacturing cost and that’s why microbial sources of enzymes are important. However, genetically engineered strains or engineered proteases have much more importance over natural isolates/protease in industries due to higher production rate and other advantages. Here we have also summarized the important applications of protease in different industries such as, paper mill, starch degrading sector, food processing factories, and detergent making companies.     

The influence of feedstock supply risk on location of stover‐based bio‐gasoline plants

This study models and quantifies spatially referenced probability distributions of corn residue cost and assesses their influence on comparative advantages of different areas of the Corn Belt to attract biofuel plants. Results suggest that irrigated areas of the Corn Belt, despite their relatively low planting density, may result more attractive than some of their rainfed counterparts in the eastern Corn Belt due to low risk in feedstock cost resulting from stability of yields. Therefore, agricultural districts in the Great Plains of the US may not need to pay high subsidies to compete with those in the eastern Corn Belt to attract biofuel firms. Policy restrictions on irrigation due to concerns over groundwater depletion may, however, diminish the relative comparative advantage of the irrigated Corn Belt for biofuel production.     

Synthesis of novel estrone analogs by incorporation of thiophenols via conjugate addition to an enone side chain

Functionalized estrogen analogs have received interest due to their unique and differing biological activity compared to their parent compounds. The synthesis of a new class of 3-methoxyestrone analogs functionalized at the C17 position possessing both alkyl and aryl substituted α,β-unsaturated ketones is described, along with their thiophenol conjugate addition products.     

Negative effect of ayu on the growth of omnivorous pale chub in experimental pools

The growth rate of pale chub Zacco platypus was negatively correlated with the number and biomass of ayu Plecoglossus altivelis in experiment pools regardless of their body weight. Both species were omnivorous, feeding upon both benthic algae and invertebrates; ayu fed principally upon algae whereas pale chub consumed invertebrates. Pale chub shifted their moving tactics from bottom moving to surface moving or sit-and-wait when they coexisted with numerous ayu, presumably due to occasional attack by ayu. It seems likely that the reduced pale chub growth rate was due to interspecific aggression and exploitation of benthic algae and invertebrates by ayu.     

Differential consumption of scleractinian and non-scleractinian coral larvae by planktivorous damselfishes

Coral Reefs - Planktivorous fishes are known to consume coral larvae due to their high nutritional value that can benefit both the individual and their progeny. However, how the consumption of...