Linking small pelagic fish and cetacean distribution to model suitable habitat for coastal dolphin species,Delphinus delphis and Tursiops truncatus,in the Greek Seas (Eastern Mediterranean)

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Exposure assessment of professional pesticide users during treatment of potato fields

In this study four different mixing/loading and application practices in potato fields were monitored for exposure of operators to pesticides. Each operation – mixing, loading, and application – was measured individually in order to assess its relative contribution to the total exposure value. Inhalation exposure was measured by trapping the pesticides with a sorbent tube while sampling the air around the operator's face. Dermal deposition, which was measured by means of cotton gloves on the hands and by attaching patches to the operator's clothing, was the main contributor to the total exposure. Dermal deposition on the hands during mixing and loading exceeded all other dermal values. The experimental results are compared with the results obtained by the exposure assessment model PHED V1.1. This model gives an underestimation of the levels of operator exposure during mixing, loading and application. © 1999 Society of Chemical Industry     

响应面法优化复合酶制取苹果梨汁工艺

以苹果梨为原料,在单因素试验的基础上,通过响应面法对复合酶制取苹果梨汁工艺参数进行优化。结果表明,复合酶制取苹果梨汁最佳工艺条件为:果胶酶添加量0.07 g/100 g,纤维素酶添加量0.11 g/100 g,酶解时间82 min,酶解温度48℃,该条件下苹果梨的出汁率可达87.6%,与未经酶处理所得苹果梨出汁率69.8%相比,提高了25.5%,说明复合酶处理可显著提高苹果梨出汁率。     

聚丙烯微塑料添加对大豆和花生生长及生理生态特征的影响

农田微塑料污染对作物生长存在显著影响,但不同功能类型作物的生理生态、产量及品质对土壤微塑料的响应尚不清楚。鉴于此,本研究选取我国农业生产的两大主要作物大豆（地上结实）和花生（地下结实）为试验材料,并设置对照组（无添加）和实验组（添加0.40%的聚丙烯微塑料）进行大田原位试验。结果表明：微塑料添加与作物结实类型二者的交互作用对作物的生长与生理生态特征存在显著影响,主要体现在作物的整株形态结构、生物量积累与分配及籽粒品质。微塑料添加显著降低两种作物的总生物量、地上生物量、相对生长速率和百粒重,大豆降幅分别为13.61%、14.07%、13.23%和7.84%,花生降幅分别为17.10%、18.64%、16.12%和11.98%。此外,微塑料添加显著降低花生的地下生物量、可溶性糖含量和大豆的叶绿素含量,降幅分别为15.77%、25.51%和5.74%,与之相反,微塑料添加增加大豆的叶面积比值和可溶性糖含量,增幅分别为28.07%和25.82%。由此可见,聚丙烯微塑料添加对两种作物的生长和产量均有抑制作用,对花生的影响尤为明显。     

Influence of revegetation efforts on hydrologic response and erosion,Kaho'olawe Island,Hawai'i

Measurements of soil physical and hydrological properties provide the first evaluation of the success of revegetation efforts in reducing surface runoff and accelerated erosion on the largely barren plateau region of Kaho'olawe Island, Hawai'i. Saturated hydraulic conductivity and sorptivity data, collected within four of the largest restoration sites, suggest revegetated areas have significantly higher infiltration capacities compared with those of the bare areas surrounding the project sites. Furthermore, comparison of modeled steady-state infiltration capacity to one-min rainfall intensities demonstrate erosion-producing Horton overland flow is very rare on the vegetated areas compared with the barren landscape. Thus, recently, established vegetation forms zones of high infiltration capable of absorbing both rainwater and surface flow exported from upslope areas. However, the current areal extent and spatial arrangement of vegetation is not sufficient to significantly reduce watershed-scale runoff and erosion. © 1998 John Wiley & Sons, Ltd.     

A theoretical study of discriminating parameters in metabolic resistance to insecticides

In the case where resistance to an insecticide is associated with increased metabolism of the insecticide, it should not be concluded that the resistance is due only to the increased metabolism (i.e. metabolic hypothesis). Here, we study theoretically the pharmacokinetic consequences of a resistance mechanism due to increased metabolism. We consider two cases: treatment with the initial dose D₀ applied to the susceptible strain and the treatment with the initial dose αD₀, with α>1, applied to the resistant strain. We show the conditions for which the metabolism hypothesis is conceivable. The time τ, from which the mortality of the susceptible strain is significantly higher than that of the resistant strain, is an important parameter in determining the validity of the metabolic hypothesis. The more τ increases, the more the conditions are favourable to this hypothesis. Our work suggests an approach to test the metabolic hypothesis from experimental results. © 1998 SCI     

Perspectives of Using L-Tryptophan for Improving Productivity of Agricultural Crops: A Review

Plant growth regulators are biologically active signaling molecules that regulate a number of plant physiological processes. Auxin (indole-3-acetic acid) is an important plant growth regulator and is synthesized within plant tissues through L-tryptophan (L-TRP)-dependent and -independent pathways. It has been found that plants respond to exogenously applied L-TRP due to insufficient endogenous auxin biosynthesis. The exogenous application of L-TRP is highly significant for normal plant growth and development. L-tryptophan is applied through foliar spray, seed priming, and soil application. Soil-applied L-TRP is either directly taken up by plants or metabolized to auxin by soil microbiota and then absorbed by plant roots. Similarly, foliar spray and seed priming with L-TRP stimulates auxin synthesis within plants and improves the growth and productivity of agricultural crops. Furthermore, L-TRP contains approximately 14% nitrogen (N) in its composition, which is released upon its metabolism within a plant or in the rhizosphere and plays a role in enhancing crop productivity. This review deals with assessing crop responses under the exogenous application of L-TRP in normal and stressed environments, mode of action of L-TRP, advantages of using L-TRP over other auxin precursors, and role of the simultaneous use of L-TRP and auxin-producing microbes in improving the productivity of agricultural crops. To the best of our knowledge, this is the first review reporting the importance of the use of L-TRP in agriculture.     

基于GWR模型的江西省山洪灾害区域异同性研究

[目的]探索山洪灾害空间分布的规律,为江西省山洪灾害防治和各流域的监测和管理提供重要决策支持。[方法]根据山洪灾害的形成机理,从触发因子、孕灾环境、承灾体3个方面选取9个解释变量,将山洪灾害调查数据的5项内容作为反应变量,并作为评价山洪灾害度的指标,利用地理加权回归方法(GWR)构建模型,然后利用GIS技术探讨江西省3个不同区域山洪灾害空间分布的异同性。[结果]同一区域不同山洪灾害度指标的模型之间具有异同性,不同区域同一山洪灾害度指标的模型之间也具有异同性,不同灾害度指标的空间分布也表现出明显的异同性。[结论]在构建各项灾害度指标模型时,不仅要考虑到地域上的差异,也要考虑到不同灾害度指标之间的差异,GWR模型能有效地解释局部空间变化情况和重要解释变量的分异性。     

马铃薯生全粉中不饱和脂肪酸微波萃取工艺参数优化及应用

为了优化马铃薯生全粉不饱和脂肪酸的微波萃取工艺,该试验采用软件Design-Expert 8.05分析以及响应面法来优化马铃薯生全粉中不饱和脂肪酸微波萃取工艺,得出马铃薯生全粉中不饱和脂肪酸的萃取模型P=0.000 10.01,R2=0.939 8,并确定马铃薯生全粉中不饱和脂肪酸最佳萃取工艺:萃取温度81℃,萃取时间11 min,萃取溶剂中丙酮占比0.802 5,料液比3.25∶1,各因素对不饱和脂肪酸质量分数影响大小分别为:丙酮占比料液比萃取温度萃取时间,实测不饱和脂肪酸质量分数为1.081 mg/g和拟合方程的预测值1.084 mg/g基本一致。将该优化方案应用于热风干燥温度对马铃薯生全粉中不饱和脂肪酸含量影响的分析中,结果表明:随着干燥温度的升高,亚油酸质量分数显著增加(P0.05),总不饱和脂肪酸质量分数增加(P0.05)。优化试验为热风干燥条件对马铃薯品质影响的研究提供了理论依据。     

伊犁绢蒿种子黏液提取工艺及对畜禽粪便污水的净化效果

伊犁绢蒿种子遇水能分泌黏液,黏液物质具有良好的保水性、成膜性、增稠性和分散性,可作为新的天然絮凝剂应用于污水处理中。该文就影响黏液提取率的3个因素提取时间、液料比、提取温度进行探讨,同时用所提取的种子黏液对牛、猪粪便污水进行处理。响应面法结果表明,绢蒿种子黏液在该试验条件下的最高提取率为16.76%,提取条件为：提取时间3 h、液料比60∶1、提取温度64 ℃;畜禽粪便废水处理试验表明,牛粪便废水处理在黏液投加量为50 mg/L时,絮凝率为28%和COD去除率为32.7%;pH值等于6时,絮凝率为46%,COD去除率为44.6%。明矾的联合使用对絮凝有显著的效果,絮凝率和COD去除率最大分别为72.3%和61.3%。猪粪便处理过程中,在黏液投加量为20 mg/L时,絮凝率为30.9%,COD去除率为32.7%,在pH值为7时,絮凝率为29.3%,COD去除率为50%,明矾的联合使用下,絮凝率和COD去除率最大分别为62.6%和68.3%,达到了预想的处理效果。研究可为伊犁绢蒿种质资源在畜禽粪便污水处理方面的开发应用提供参考。