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采用子结构模式识别结合5种机器学习方法(包括支持向量机、C4.5决策树、k-最近邻法、随机森林法、和朴素贝叶斯法),分别构建了有机化合物对水生和陆地环境毒性评价的两个重要生物靶标——呆鲦鱼(Fathead minnow)和蜜蜂毒性的定性分类和定量回归预测模型。所有模型均通过独立测试集验证。其中,利用支持向量机分类算法得到的分类模型对呆鲦鱼和蜜蜂毒性测试集的整体预测准确度分别达到95.9%和95.0%。采用支持向量机回归算法得到的回归模型,对呆鲦鱼和蜜蜂毒性测试集的预测相关系数的平方(R2)分别达到0.878和0.663。最后,通过信息熵分析的方法,确定了一批能够代表性地表征呆鲦鱼和蜜蜂毒性的子结构模式,包括1,2-二酚、二烷基硫醚、二芳香醚和磷酸衍生物等。提出的方法为有毒化学品的生态风险评价提供了一种非常好的评价策略和可靠的工具。 相似文献
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从4月中旬至11月初,以乐果作为参比药剂,采用急性接触毒性试验方法,在北京跟踪测试了同一箱蜜蜂对农药的敏感性变化趋势。结果表明,不同月份蜜蜂对乐果的敏感性呈连续的单峰曲线分布,仅在5月底到10月初之间采集的蜜蜂的敏感性符合OECD试验准则和GB/T 31270.10中有关参比物毒性试验结果的要求,即乐果对蜜蜂急性接触毒性24hLD50应在0.10~0.30μg a.i./蜂范围内,其他时间的蜜蜂敏感性不符合试验要求。因此,建议在北京及周边地区,宜采用6-10月份的蜜蜂用于农药登记用毒性试验。 相似文献
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为给我国稻纵卷叶螟Cnaphalocrocis medinalis防治提供前期预警,使用R语言软件对我国15个省市区稻纵卷叶螟发生等级与全球海温场资料进行遥相关分析,绘制相关系数的时空间分布图,筛选出显著相关海温区作为预测因子,根据各省市区虫情数据组建回归模型+判别模型、BP神经网络模型和支持向量机(SVM)模型,比较3种模型的历史回检率和预测完全准确率。结果显示,3种模型对稻纵卷叶螟发生等级均有一定的预测能力,其中判别模型+回归模型效果最好,预检完全准确率可达到75.0%,BP神经网络模型次之,预检完全准确率为68.2%,SVM模型预测效果最差,预检完全准确率为54.5%。进一步分析建模所使用的50个预测因子的空间位置,在南印度洋和北大西洋确定3个预测指标,预检准确率为94.4%。通过海温场数据建立的我国15个省市区稻纵卷叶螟发生等级预测模型,适用于长期预测预报。判别模型+回归模型更适合在样本量少、预测因子相关性强的地区建模,而根据预测因子空间分布选择的预测指标进行定性预测准确率更高。 相似文献
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氟氯氰菊酯和高效氯氟氰菊酯是两种常见的拟除虫菊酯类杀虫剂，因对水生生物具有高毒性，其环境风险有待进一步评估。本研究以斑马鱼胚胎为模型，将其连续暴露于两种农药下96 h，期间分别测定了受精后24 h胚胎自主运动、受精后48 h仔鱼心率和孵化率、受精后96 h仔鱼畸形率和死亡率等指标，以评价两种农药对斑马鱼的胚胎发育毒性，并采用基准剂量(BMD)法分析比较了两种药剂的胚胎发育毒性敏感指标，探究了BMD法在评价农药环境风险中的应用前景。BMD法计算结果显示，评价氟氯氰菊酯毒性时最敏感的指标为受精后48 h仔鱼心率，评价高效氯氟氰菊酯毒性时最敏感的指标为受精后48 h孵化率，且氟氯氰菊酯最敏感指标的毒性阈值(基准剂量置信区间下限，BMDL10)更低。此外，针对两种农药的绝大多数胚胎发育毒性指标计算所得的BMDL10值均低于对应的最小可见损害作用水平(LOAEL) 。结果提示，BMD法不仅可用于比较相同种类不同农药的毒性差异，还能充分准确地挖掘实验数据，可为农药的环境风险评估提供新的思路和策略。 相似文献
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对河南省夏玉米区2003年-2018年玉米茎腐病发生、流行情况进行分析,选择制约茎腐病发生流行的主要气象因素,采用判别分析法建立茎腐病发生的两阶段预测模型。应用2003年-2014年的数据进行模型训练,利用2015年-2018年数据进行测试。结果表明,第一阶段预测模型历史回代自身验证准确率为86%,交互验证准确率为79.1%;第二阶段自身验证准确率为83.7%,交互验证准确率为76.7%。应用2015年-2018年数据进行测试,第一阶段预测准确率75%,第二阶段预测准确率85%。说明利用判别分析建立玉米茎腐病流行模型是可行的。 相似文献
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为研究农产品中农药混合污染的联合毒性,选取生菜中应用广泛、广谱性强的5种农药(苯醚甲环唑、氯氰菊酯、烯酰吗啉、氯氟氰菊酯和啶虫脒)及其高频检出的二元、三元农药组合为研究对象,采用CCK-8 (Cell Counting Assay Kit-8) 法探究农药单剂及混合物对人肝癌HepG2细胞增殖的抑制毒性,基于单个农药剂量效应曲线按照等效应的联合毒性测定方法,应用浓度相加、独立作用和联合指数3个预测模型推导联合效应,并通过高内涵筛选系统分析农药混合物对人肝癌HepG2细胞凋亡的诱导作用。结果表明:不同农药对HepG2细胞增殖抑制的影响存在较大差异,但均具有明显的剂量-效应关系,其中苯醚甲环唑具有最强的细胞增殖抑制毒性,细胞活力的半数抑制浓度 (EC50) 为24.72 μmol/L;其余农药毒性顺序为烯酰吗啉 > 氯氟氰菊酯 > 啶虫脒 > 氯氰菊酯。通过联合指数判定农药混合物的联合毒性效应的结果表明:所有二元组合均随农药浓度增大表现出细胞增殖抑制效应增强,联合效应由拮抗转为协同;三元组合烯酰吗啉 + 苯醚甲环唑 + 氯氰菊酯、烯酰吗啉 + 氯氰菊酯 + 啶虫脒的细胞增殖抑制效应分别为60%和18%时,联合效应由协同转为拮抗。同时,利用剂量减少指数量化农药混合物之间的协同效应研究表明,在上述两个三元组合的协同效应中,氯氰菊酯发挥较大作用。在凋亡毒性测定中,各农药单独处理组均会造成HepG2细胞凋亡率的显著提高,且呈剂量依赖性;三元组合烯酰吗啉 + 氯氰菊酯 + 啶虫脒在20.02~80.10 μmol/L浓度范围内可诱导细胞凋亡水平显著提升。本研究明确了农药单剂和混合物对HepG2细胞增殖和凋亡毒性具有明显的剂量依赖效应,可为混合农药毒性评价以及风险监测提供科学依据。联合指数模型可以定量地描述农药混合物在不同组分和浓度下的相互作用,对比浓度相加和独立作用模型,可较准确地预测混合物的联合毒性,是一种有效的生态毒理学风险评估工具。 相似文献
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氨基甲酸酯类农药被广泛用于农业生产中，其作用机理主要是通过与乙酰胆碱酯酶共价结合，从而抑制其正常的生物活性，但此类农药的无节制使用导致其大量残留于生态环境中，对整个生态系统的生存安全造成了严重威胁。本文作者基于量化反应性指数，采用遗传/偏最小二乘法，对氨基甲酸酯与其对乙酰胆碱酯酶的抑制活性进行了定量构效关系研究。结果表明:预测方程的决定系数 (R2) 均在0.8以上，采用留一法和自举法交叉验证的R2均在0.7以上；一致性模型的R2为0.823，均方根误差为0.369，获得了较好的预测模型。同时发现，量化反应性指数的引入有效增强了模型的可解释性，有助于进一步探索和验证氨基甲酸酯与乙酰胆碱酯酶的作用机理。本文所得到的模型可为氨基甲酸酯类农药的活性预测和风险评估提供理论依据。 相似文献
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In this study, cell death detected by DNA fragmentation labeling and phosphatidylserine (PS) localization was investigated in the honey bee (Apis mellifera L.) midgut, salivary glands and ovaries after treating larvae with different pesticides offered via an artificial diet. To do this, honey bee larvae reared in an incubator were exposed to one of nine pesticides: chlorpyrifos, imidacloprid, amitraz, fluvalinate, coumaphos, myclobutanil, chlorothalonil, glyphosate and simazine. Following this, larvae were fixed and prepared for immunohistologically detected cellular death using two TUNEL techniques for DNA fragmentation labeling and Annexin V to detect the localization of exposed PS specific in situ binding to apoptotic cells. Untreated larvae experienced ∼10% midgut apoptotic cell death under controlled conditions. All applied pesticides triggered an increase in apoptosis in treated compared to untreated larvae. The level of cell death in the midgut of simazine-treated larvae was highest at 77% mortality and statistically similar to the level of cell death for chlorpyrifos (65%), imidacloprid (61%), myclobutanil (69%), and glyphosate (69%) treated larvae. Larvae exposed to fluvalinate had the lowest midgut columnar apoptotic cell death (30%) of any pesticide-treated larvae. Indications of elevated apoptotic cell death in salivary glands and ovaries after pesticide application were detected. Annexin V localization, indicative of apoptotic cell deletion, had an extensive distribution in the midgut, salivary glands and ovaries of pesticide-treated larvae. The data suggest that the tested pesticides induced apoptosis in tissues of honey bee larvae at the tested concentrations. Cell death localization as a tool for a monitoring the subclinical and sub-lethal effects of external influences on honey bee larval tissues is discussed. 相似文献
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四种新烟碱类杀虫剂对蜜蜂的急性毒性及初级风险评估 总被引：2，自引：1，他引：1
采用饲喂管法和点滴法,分别测定了吡虫啉、噻虫嗪、噻虫胺、啶虫脒4种原药及其制剂对意大利蜜蜂成年工蜂的急性毒性,并采用危害商值(HQ)法进行了初级风险评价。结果表明:饲喂管法测得97.3%吡虫啉原药、25%吡虫啉可湿性粉剂、96%噻虫嗪原药、30%噻虫嗪悬浮剂、97%噻虫胺原药、5%噻虫胺可湿性粉剂、96%啶虫脒原药及40%啶虫脒可溶性粉剂的经口毒性48 hLD50值分别为有效成分8.04×10-3、9.46×10-3、7.04×10-3、4.64×10-3、11.8×10-3、5.25×10-3、5.22和6.31μg/蜂;点滴法测得各药剂的接触毒性48 h-LD50值分别为有效成分2.46×10-2、1.33×10-2、3.63×10-2、9.27×10-3、1.52×10-2、2.21×10-2、5.82和5.07μg/蜂。按《化学农药环境安全评价试验准则》的毒性等级划分标准,啶虫脒原药及其可溶性粉剂对蜜蜂的急性毒性均为中等毒,其他6种药剂对蜜蜂的急性毒性均为高毒;根据危害商值(HQ),啶虫脒对蜜蜂为低风险,吡虫啉、噻虫嗪和噻虫胺对蜜蜂均存在高风险。 相似文献
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To evaluate the effect of the indoxacarb 300 g kg(-1) WG, Steward 30WDG, on the honey bee (Apis mellifera L.) in apple orchards, a monitoring study was conducted in Dutch apple orchards in April/May 2004. Before apple flowering began, two honey bee colonies were placed in each orchard to investigate honey bee mortality. Each hive was provided with a Münster dead bee trap to collect dead honey bees. The numbers of dead bees found in these Münster dead traps were counted every 3-4 days for about 2 weeks before and after the period of the insecticide treatment. In nine flowering orchards no indoxacarb was applied during the flowering period, which served as control sites. In 30 flowering orchards indoxacarb was sprayed by the fruit growers according to local practice at 170-260 g formulated product ha(-1) (51-78 g AI ha(-1)). In the control orchards the average mortality was 8 honey bees colony(-1) day(-1). The average daily honey bee mortality before and after indoxacarb application was 8 and 10 honey bees colony(-1) day(-1) respectively. At one test site, indoxacarb was mixed with other plant protection products plus plant nutrients, and in this orchard a slight but biologically non-significant increase in acute honey bee mortality was recorded. It was concluded that the application of indoxacarb caused no effects on honey bee mortality, and that the number of dead honey bees counted in the Münster traps in the orchard treated with indoxacarb was comparable with those determined in control orchards. 相似文献
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BACKGROUND: Previous work has characterised pyrethroid resistance in pollen beetle (Meligethes aeneus F.) as principally an oxidative mechanism. Piperonyl butoxide (PBO) can synergise this resistance in the field, but its effects on the honey bee are thought to be unacceptable. RESULTS: A field trial in Poland was conducted to show that a mixture of PBO and tau‐fluvalinate at the registered rate gave increased and longer‐lasting control of resistant pollen beetle. Four days after spraying with tau‐fluvalinate, only 20% of pollen beetles were controlled, compared with 70% if the tau‐fluvalinate/PBO mixture was used. No detriment to honey bee health was observed using the same mixture. CONCLUSIONS: PBO, if used in conjunction with a pyrethroid of relatively low bee toxicity, can successfully overcome pyrethroid resistance in pollen beetle without incurring an increased loss of honey bees, even if they are present at the time of spraying. Copyright © 2012 Society of Chemical Industry 相似文献
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雷帕霉素为大环内脂类抗生素药剂,对多种人类疾病有效,近年发现其对多种植物病原真菌也有较好的抑制活性,有望开发为微生物源农药用于植物病害的防治,而目前关于雷帕霉素的水解行为及其对非靶标生物的急性毒性还未见报道。为评价雷帕霉素的水解行为及其对非靶标生物的急性毒性,本研究通过室内模拟试验,测定了雷帕霉素在不同pH值、温度、初始浓度及光源中的水解特性,同时测定了其对家蚕、意大利工蜂、斑马鱼及赤子爱胜蚯蚓4种非靶标生物的急性毒性。水解试验结果表明:碱性环境、紫外光照及高温有利于雷帕霉素的水解。当其初始质量浓度为10 mg/L时,半衰期分别为66.63、38.93及77.00 h;初始质量浓度为50 mg/L时,半衰期分别为144.38、105.00及165.00 h。急性毒性试验结果表明:雷帕霉素对家蚕和斑马鱼的96 h-LC50值分别为 386.46和3.50 mg/L (有效成分,下同);对意大利工蜂的急性经口毒性48 h-LD50值为8.95 μg/bee,急性接触毒性48 h-LD50值为16.79 μg/bee;对赤子爱胜蚯蚓的14 d-LC50值为223. 81 mg/kg。按照 “化学农药环境安全评价准则” (GB/T 31270—2014) 的毒性等级划分标准,雷帕霉素对家蚕、斑马鱼、赤子爱胜蚯蚓的急性毒性分别为 “低毒”、“中毒” 和 “低毒”,对意大利工蜂的急性经口毒性为 “中毒”,急性接触毒性为 “低毒”。研究表明,雷帕霉素属于易降解性药剂,对家蚕、意大利工蜂、斑马鱼及赤子爱胜蚯蚓4种非靶标生物安全。 相似文献
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BACKGROUND: Honey bees (Apis mellifera L.) are among the most important pollinators in natural and agricultural settings. They commonly encounter insecticides, and the effects of insecticides on honey bees have been frequently noted. It has been suggested that honey bees may be (as a species) uniquely sensitive to insecticides, although no comparative toxicology study has been undertaken to examine this claim. An extensive literature review was conducted, using data in which adult insects were topically treated with insecticides. The goal of this review was to summarize insecticide toxicity data between A. mellifera and other insects to determine the relative sensitivity of honey bees to insecticides. RESULTS: It was found that, in general, honey bees were no more sensitive than other insect species across the 62 insecticides examined. In addition, honey bees were not more sensitive to any of the six classes of insecticides (carbamates, nicotinoids, organochlorines, organophosphates, pyrethroids and miscellaneous) examined. CONCLUSIONS: While honey bees can be sensitive to individual insecticides, they are not a highly sensitive species to insecticides overall, or even to specific classes of insecticides. However, all pesticides should be used in a way that minimizes honey bee exposure, so as to minimize possible declines in the number of bees and/or honey contamination. Copyright © 2010 Society of Chemical Industry 相似文献
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Pesticides and reduced‐risk insecticides,native bees and pantropical stingless bees: pitfalls and perspectives 
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下载免费PDF全文 Although invertebrates generally have a low public profile, the honey bee, Apis mellifera L., is a flagship species whose popularity likely derives from the products it provides and its perceived ecological services. Therefore, the raging debate regarding honey bee decline has surpassed the realm of beekeepers, academia, industry and regulatory agencies and now also encompasses non‐governmental agencies, media, fiction writers and the general public. The early interest and concern about honey bee colony collapse disorder (CCD) soon shifted to the bigger issue of pollinator decline, with a focus on the potential involvement of pesticides in such a phenomenon. Pesticides were previously recognised as the potential culprits of the reported declines, particularly the neonicotinoid insecticides owing to their widespread and peculiar use in agriculture. However, the evidence for the potential pivotal role of these neonicotinoids in honey bee decline remains a matter of debate, with an increased recognition of the multifactorial nature of the problem and the lack of a direct association between the noted decline and neonicotinoid use. The focus on the decline of honey bee populations subsequently spread to other species, and bumblebees became another matter of concern, particularly in Europe and the United States. Other bee species, ones that are particularly important in other regions of the world, remain the object of little concern (unjustifiably so). Furthermore, the continuous focus on neonicotinoids is also in need of revision, as the current evidence suggests that a broad spectrum of compounds deserve attention. Here we address both shortcomings. © 2015 Society of Chemical Industry 相似文献