基于模糊最优小波包的植物胁迫因子识别

为了正确地识别植物常见的胁迫种类,以采集的正常状态和7种胁迫下的植物电信号为样本,结合小波包分解提取特征值能力强的优点,应用模糊准则来优化小波包分解,提取植物电信号中的最优小波包基能量值构成特征集,应用更适合处理模糊的、非线性信号的BP神经网络作为分类器,以实现对不同逆境因子类型的识别.首先利用小波包对采集的植物电信号进行降噪预处理,然后列举了样本经基于模糊准则的小波包处理后各小波包基上的能量样本值,绘制了特征分布图,最后通过对芦荟、碧玉、虎皮兰和蟹爪兰4种植物所处7种胁迫的判断,以统计特征值作为对照,采用所提方法胁迫平均识别率达到95.95％,验证了此方法的准确性和可行性.     

He-Ne激光辐照对大豆幼苗异黄酮含量的影响

用波长为632.8 nm的He-Ne激光辐照大豆种子胚,研究辐照时间对发芽率、幼苗株高及幼苗子叶、叶片和茎中大豆异黄酮含量的影响。结果表明:大豆种子胚经3.6 mW/mm2激光辐照1～7 min后,其发芽率、幼苗株高、幼苗苯丙氨酸转氨酶(PAL)活性、游离苯丙氨酸(Phe)和大豆异黄酮含量均高于对照组(ck)。其中以幼苗叶辐照5 min后和子叶辐照7 min后,大豆异黄酮含量的提高最为明显,分别为42.6%和36.7%。本研究还从大豆异黄酮合成代谢起始酶PAL活性、合成前体Phe含量两方面探讨了激光辐照大豆种子胚提高其幼苗大豆异黄酮含量的机理。     

基于猕猴桃采后生理的主成分分析及其与电学指标相关性研究

[目的]通过对无损检测中电学参数与生理指标综合信息关系和特征频率进行研究,对猕猴桃采后生理贮藏期进行预测。[方法]对贮藏过程中果肉硬度等10种生理指标进行主成分分析并探讨其与相关电学参数的关系。[结果]对猕猴桃采后贮藏过程中失重率、硬度和含水量等10种生理指标进行测定并进行主成分分析,建立的主成分综合模型能够全面反映猕猴桃生理状态的变化;通过计算主成分值F,可对猕猴桃的采后贮藏期进行预测。在0.1～39.8 kHz频率段,3种电学参数与生理指标的主成分值相关性较好,可作为猕猴桃采后生理的无损检测频率,且在0.1～39.8 kHz频率范围内可进行猕猴桃的损伤果和正常果的区分;63.1 kHz可作为猕猴桃的特征检测频率。[结论]该研究为猕猴桃及相关水果贮藏期的预测和无损检测提供了理论依据。     

全氟辛烷磺酸污染研究进展

全氟辛烷璜酸（PFOS）是一种新型的持久性有机污染物（POPs）,也是目前最难降解的有机污染物之一。文章对PFOS在环境中（水体、沉积物）、动物体内及人群中的污染情况和暴露水平进行综述,提出今后应进一步对PFOS毒作用敏感指标及毒作用机制进行探讨与研究,研究和改进实验手段和检验设备,加大全国各地PFOS污染状况和健康影响调查、研究PFOS的时空分布规律及其在各环境介质中（主要是空气—水—土—底泥）的迁移、积累和转化,并通过数值模拟方法得到关于时空变化规律的数学模型,探索PFOS的修复治理技术,使PFOS对环境的影响降到最低。     

高毒有机磷农药慢性危害评估方法研究

为探索高毒有机磷农药残留对人群慢性危害的评估方法,本文以江苏省甲胺磷、甲拌磷、对硫磷、甲基对硫磷以及氧乐果在蔬菜中残留的实测数据和文献中相关参数为基础资料,采用饮食暴露模型(DEEM)估算江苏省人群对蔬菜中这5种有机磷农药残留的暴露水平,分别采用参考剂量百分比、暴露边缘以及日允许摄入量百分比3种评估方法从不同角度对其慢性危害进行分析。危害分析结果表明:江苏省人群对蔬菜中这5种有机磷农药的暴露水平目前仍属于安全范围。3种评估方法同时对慢性危害进行评估,可以避免遗漏高风险农药,同时量化农药的慢性危害。     

Synthesis of a base-stock for electrical insulating fluid based on palm kernel oil

This report presents a method for synthesizing base-stock for green industrial product from a vegetable oil with a high composition of unsaturated fatty acids. Epoxy methyl ester of palm kernel oil was synthesized from laboratory purified palm kernel oil using a two-step reaction and the products were used as a base-stock for green electrical insulation fluid. Epoxidized palm kernel oil was first prepared through epoxidation reaction involving purified palm kernel oil, acetic acid and hydrogen peroxide in the presence of amberlite as catalyst which lasted for 4 h. It was then followed by transesterification reaction involving the epoxidized product and methanol in the presence of sodium hydroxide as catalyst to synthesize the corresponding epoxy methyl ester. The thermal and electrical breakdown properties of the epoxy methyl ester demonstrated significantly improved properties for its use as raw material for bio-based industrial products such as electrical insulation fluids.     

Three years of banning neonicotinoid insecticides based on sub‐lethal effects: can we expect to see effects on bees?

The 2013 EU ban of three neonicotinoids used in seed coating of pollinator attractive crops was put in place because of concern about declining wild pollinator populations and numbers of honeybee colonies. It was also concluded that there is an urgent need for good field data to fill knowledge gaps. In the meantime such data have been generated. Based on recent literature we question the existence of recent pollinator declines and their possible link with the use of neonicotinoids. Because of temporal non‐coincidence we conclude that declines of wild pollinators and of honeybees are not likely caused by neonicotinoids. Even if bee decline does occur and if there is a causal relationship with the use of neonicotinoids, we argue that it is not possible on such short term to evaluate the effects of the 2013 ban. In order to supply future debate with realistic (field) data and to discourage extrapolating the effects of studies using overdoses that are not of environmental relevance, we propose – in addition to field studies performed by the chemical industry – to use the ‘semi‐field worst case’ treated artificial diet studies approach to free flying colonies in the field. This kind of study may provide realistic estimates for risk and be useful to study realistic interactions with non‐pesticide stressors. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Effects of acute cold exposure on oxidative balance and total antioxidant capacity in juvenile Chinese soft‐shelled turtle,Pelodiscus sinensis

Acute cold exposure may disturb the physiological homeostasis of the body in ectotherms. To date, there has been no information on the effects of cold exposure on homeostasis of reactive oxygen species (ROS) or antioxidant defense response in the Chinese soft‐shelled turtle, Pelodiscus sinensis. In this study, P. sinensis juveniles were acclimated at 28 °C, transferred to 8 °C as cold exposure for 12 h, then moved back to 28 °C rewarming for 24 h. We measured the ROS level and total antioxidant capacity (TAC) in the brain, liver, kidney and spleen at 2 and 12 h cold exposure, and at the end of the rewarming period. Malonaldehyde (MDA) and carbonyl protein were used as markers of oxidative damage. Turtles being maintained simultaneously at 28 °C were used as the control group. Cold exposure did not disturb the ROS balance in all 4 tissues, while rewarming raised the ROS level in the brain and kidney of P. sinensis. Cold exposure and rewarming decreased the TAC in the brain, liver and spleen but did not change the TAC in the kidney. MDA and carbonyl protein levels did not increase during the treatment, indicating no oxidative damage in all 4 tissues of P. sinensis. Our results indicated that extreme cold exposure did not impact the inner oxidative balance of P. sinensis, but more ROS was produced during rewarming. P. sinensis showed good tolerance to the harsh temperature change through effective protection of its antioxidant defense system to oxidative damage. This study provides basic data on the stress biology of P. sinensis.     

短时高温处理对意大利蝗卵子发生期HSP70蛋白表达的影响

本研究采用免疫组织化学分析方法,测定了HSP70蛋白在意大利蝗卵子发生期的表达定位及33~42℃高温处理对其相对表达量的影响。结果表明,1)在卵黄发生前期,卵母细胞和滤泡细胞均表达HSP70蛋白,而在卵黄发生期和卵黄发生后期,HSP70蛋白阳性表达位于滤泡细胞;2)在33~42℃温度范围内,随着温度升高,意大利蝗卵子发生期HSP70蛋白相对表达量呈现先上升后下降的变化趋势;其中36℃处理组HSP70蛋白相对表达量最高,显著高于27℃对照组(P0.05);42℃处理组HSP70蛋白相对表达量最低,但与27℃对照组差异不显著(P0.05)。短时高温处理对意大利蝗卵子发生期HSP70蛋白相对表达量有显著影响,推测HSP70蛋白的表达在意大利蝗抵抗短时高温胁迫过程中具有重要作用。