The effect of aqueous extract of gross and commercial yerba mate (Ilex paraguariensis) on intra-abdominal and epididymal fat and glucose levels in male Wistar rats

This study analyzed the plasma lipid profile, glucose levels and fat deposits in male rats treated with aqueous extract of gross yerba mate, commercial yerba mate or water. Yerba mate treatment did not change body weight gain and lipid profile. The consumption of gross yerba mate significantly increased blood glucose (6.6 mmol/L) as compared to the water (4.8 mmol/L) and commercial group (5.2 mmol/L) and decreased epididymal and intra-abdominal deposits (10.1 mg/g and 23.7 mg/g of weight) as compared to the water (15.4 mg/g and 36.9 mg/g of weight) and commercial group (12.5 mg/g and 28 mg/g of weight). The results suggest that gross yerba mate reduces fat more efficiently but produces a greater increase in blood glucose when compared to commercial yerba mate and water groups.     

Short- and long-term effects of heavy metals on phosphatase activity in soils: An ecological dose-response model approach

Summary The aim of this study was to provide manageable data to help establish permissible limits for the pollution of soil by heavy metals. Therefore the short-and long-term effects of heavy metal pollution on phosphatase activity was studied in five different soil types. The results are presented graphically as logistic dose-response curves. It was possible to construct a curve for sand and silty loam soil but it was more difficult to establish a curve for sandy loam and clay soil and nearly impossible (except for Cu) for peat. The toxicity of the various metals can be compared on the basis of mmol values. In clay soils, for Cd, Cr, Cu, and Zn, the 50% effective ecological dose (ED₅₀) values were comparable (approximately 45 mmol kg^–1), but the ED₁₀ values were very different, at 7.4, 41.4, 15.1, and 0.55, respectively. At the ED₅₀ value, toxicity did not decrease with time and, in sandy soils, was approximately 2.6 mmol kg ^–1 dry soil for Cd, Cu, and Zn. In four out of five soils, the Cd toxicity was higher 1.5 years after the addition of heavy metal salts than after 6 weeks. Toxicity was least in the sandy loam, silty loam, and clay soil, and varied in general between 12 and 88 mmol kg^–1. In setting limits, the criteria selected (no-effect level, ED₁₀ or ED₅₀) determine the concentration and also the toxicity of the sequence. It is suggested that the data presented here could be very useful in helping to set permissible limits for heavy metal soil pollution.     

基于1:5万数据库研究土壤空间分异及其影响因素——以江苏省无锡和常州市为例

土壤数据库在土壤学研究工作中作为一种存储、分析工具的重要性是不言而喻的.本研究利用ArcGIS和Visual FoxPro建立了包括8 830个图斑、269个土壤剖面数据的无锡和常州市1：5万土壤数据库,根据“土壤质量演变规律与持续利用‘973＇项目”的土壤肥力质量指标（pH、速效磷和速效钾）和全国养分分级标准（全氮）编制出土壤表层（0～15 cm）pH、全氮、速效磷和速效钾的空间分异图,从中表明pH 1～2级的土壤占整个研究区面积90%左右;土壤养分全氮、速效磷和速效钾的空间分布有明显共同特征-太滆平田区养分含量要显著高于其他地区.对不同母质和不同土壤类型（亚类级别）间的土壤表层容重、粘粒、pH、有机质、全氮、全磷、全钾、速效磷和速效钾进行了方差分析,结果显示,除全氮之外,其他属性均有显著差异.在1：5万尺度范围内,成土母质对pH、容重、全磷、有机质和速效钾起到主导作用,土壤类型对pH起到主导作用,成土母质对土壤属性的影响程度要大于土壤类型.     

Copper in the terrestrial environment: Verification of a laboratory-derived terrestrial biotic ligand model to predict earthworm mortality with toxicity observed in field soils

This study was set up for validation of a regression model to predict mortality in the terrestrial earthworm Aporrectodea caliginosa following exposure to copper. This model was derived from a terrestrial biotic ligand model and incorporates the protective effects of H⁺ and Na⁺ on copper toxicity.Three soil sets were used for the experiments, all of which had a different copper contamination history over more than 20 years and were considered to be aged field soils. The soils were characterized by analysis of various copper pools in the solid phase and in the pore water, analysis of physical and chemical soil properties and by regression analysis. Measured and calculated copper activities (expressed as pCu) correlated reasonably well. Measured copper activities correlated with the total copper concentration in the pore water and the pH. The organic matter in the solid phase had no influence on the pCu in these soil sets.Earthworms were exposed to the soils for 28 days, after which survival was scored. Observed earthworm mortality after 28-days exposure was plotted as a function of the log-transformed difference between predicted (log₁₀ transformed) LC50-values and measured values of pCu for validation of the regression model. The results obtained were in agreement with the assumption that mortality is to be observed in those soils where the predicted LC50 exceeds the measured pCu. However, a structural underestimation of toxicity was apparent, which is most likely due to mixture effects related to the presence of additional substances in field soils. Nevertheless, the trend of the results in the validation tests demonstrates that the newly developed toxicity model is a useful tool in predicting lethality of copper contamination to earthworms in field soils.     

基于RAdam卷积神经网络的水稻生育期图像识别

为了解决现阶段水稻发育期信息的获取主要依靠人工观测的效率低、主观性强等问题,该研究提出一种基于Rectified Adam(RAdam)优化器的ResNet50卷积神经网络图像识别方法,开展水稻关键生育期的自动识别。连续2a对12块试验田的水稻物候特征进行持续自动拍摄,对采集的水稻图像进行预处理,得到水稻各发育期分类图像数据集;采用ExG因子和大津法(Otsu)算法相结合的方法对水稻图像分割,减小稻田背景干扰;对比分析了VGG16、VGG19、ResNet50和Inception v3四种模型下水稻生育期图像分级识别的性能,选取性能较优网络模型并进行了网络参数调优;对比试验了不同优化器下模型准确率和损失值的变化,选取了RAdam优化器。结果表明,采取基于RAdam优化器卷积神经网络构建的模型,在真实场景下分类识别准确率达到97.33%,网络稳定性高、收敛速度快,为水稻生育期自动化观测提供了有效方法。     

两种皂荚提取物的杀鼠活性研究

采用灌胃法测定皂荚的乙醇与丙酮提取液对小鼠的毒性大小,结果证明,乙醇提取液对小鼠的0致死的最大量(Dn)和100%致死的最小量(Dm)分别为1.5 g.kg-1、4.0 g.kg-1,致死中量LD50=2.21 g.kg-1;丙酮提取液体的Dn=2.0 g.kg-1,Dm=6.0 g.kg-1,LD50=3.52 g.kg-1。通过对致死中量测定所得结果分析,乙醇提取液的毒力大于丙酮提取液的毒力,且两者毒力均较强。     

50%嘧霉胺·多菌灵WP防治番茄灰霉病田间药效试验

[目的]明确50%嘧霉胺.多菌灵WP对番茄灰霉病的防治效果和安全性,选择其在田间的适宜用量,为该农药的推广应用提供科学依据。[方法]设置了不同浓度和与其他药剂对比的7个处理,研究各处理对防治番茄灰霉病的田间药效。[结果]结果表明,用50%嘧霉胺.多菌灵WP 600 g/hm2防治番茄灰霉病,对叶片和果实的防效分别为82.3%和81.5%,显著高于对照药剂40%欧诺SC 480g/hm2、30%齐乐WP 1 050 g/hm2和50%多菌灵WP 1 000 g/hm2的防效。[结论]在用量450~600 g/hm2的情况下,该农药防治效果可达70%~85%,对作物安全。     

禽波氏杆菌对雏鸡和鸡胚毒力的测定

本文介绍了禽波氏杆菌对雏鸡和鸡胚毒力的测定。测定结果表明,禽波氏杆菌对2日龄公雏腹腔接种的 LD_(50)为1.352×10~4个菌,对12日龄鸡胚尿囊腔内接种的 MLD 低于196个菌。     

50%翠贝干悬浮剂对香蕉黑星病的毒力测定及防治试验

香蕉黑星病是香蕉的重要病害,在华南蕉区可周年广泛发生,严重危害蕉叶和蕉果.2003～2004年采用新型杀菌剂50%翠贝千悬浮剂对香蕉黑星病菌进行毒力测定、防治试验,研究结果表明,50%翠贝干悬浮剂对香蕉黑星病菌有良好的抑制作用,防治香蕉黑星病效果优良,安全性高;施药3次后20天,50%翠贝干悬浮剂2000倍的防治效果达到80.01%,显著优于对照药剂75%百菌清可湿性粉剂800倍的防效,建议在生产上推广应用.     

二氯喹啉酸对湘云鲫鳃肝脏ATPase活性的影响及其机制探讨

采用室内实验方法,研究了二氯喹啉酸对湘云鲫的急性毒性及湘云鲫鳃、肝脏中Na -K -ATPase和Mg2 -ATPase活性的影响。结果表明:①在23℃±1℃条件下,二氯喹啉酸对湘云鲫的24,48,72,96h的LC50分别为151.64,150.92,149.60,149.14mg·L-1,是一种低毒性农药;②鱼鳃和肝脏中Na -K -ATPase、Mg2 -ATPase活性的抑制随浓度的增加而加强,随着处理时间的延长而加强,表现出显著的浓度-效应和时间-效应关系,是一种较好的生物指示剂。此外,还讨论了二氯喹啉酸抑制ATPase活性的机制。