A comparison of the effectiveness of insecticides in constant and variable thermal conditions

The effectiveness of insecticides differs with changes in temperature, but insecticide toxicities are determined at constant temperatures. Constant thermal conditions do not occur in the field, where insects can change their behaviors to achieve a preferred temperature. The aim of this study was to assess whether the choice of ambient temperature affects the mortality rate of intoxicated firebugs and Colorado potato beetles. The insects’ mortality following insecticide exposure was monitored at constant temperatures (15, 25, and 35 °C) as well as in a thermal gradient system, where the insects could freely select their preferred ambient temperature. Firebugs treated with oxadiazine showed 58% higher mortality when held at a constant temperature post-treatment compared to mortality levels seen when able to choose a preferred temperature in a thermal gradient. Similar results were seen in Colorado potato beetles treated with oxadiazine (15%–33% higher mortality in constant vs. preferred temperature) or organophosphate (36% higher mortality in constant vs. preferred temperature). The insects’ ability to mitigate the impacts of pesticide exposure by selecting more beneficial thermal conditions is an important consideration for pest management. Therefore, the application rates of insecticides used under field conditions should be additionally analyzed to take this factor into account.     

温度对绿眼赛茧蜂寄生率及生长发育的影响

绿眼赛茧蜂Zele chlorophthalmus(Spinola)是草地螟Loxostege sticticalis L.幼虫的重要寄生蜂。但目前国内外对其生物学特性及其发生与温度的关系还没有报道。为了阐明绿眼赛茧蜂的生物学特性,并为其室内扩繁及田间保护利用提供试验依据,本文分别在17、21、25、29和33℃、相对湿度70%±5%、光周期16L:8D条件下,以草地螟3龄幼虫为寄主,研究了其寄生率和生长发育特征的变异,明确了其发育起点温度和有效积温,以及在我国草地螟主要发生危害区的发生为害世代。结果表明,在17~29℃,绿眼赛茧蜂能与寄主建立寄生关系,并能完成发育。其中以21和25℃的寄生率最高(67.3%和60.0%),子代结茧率和羽化率最高(70%)并显著高于29和17℃的。另外,绿眼赛茧蜂的蛹(茧)重和成虫寿命随温度的升高而下降。但在33℃,寄生率为0,不能与草地螟建立寄生关系;在17~25℃,卵-幼虫、预蛹-蛹及世代发育历期随温度的升高而缩短,但在29℃时,发育历期比25℃的有所延长。Logistic曲线和线性模型均可描述绿眼赛茧蜂发育速率与温度的关系,但前者的决定系数(R2=0.935~0.971)比后者(R2=0.859~0.890)高,因而Logistic曲线能更好地反映绿眼赛茧蜂发育速率与温度的关系;卵-幼虫、预蛹-蛹以及世代的发育起点温度依次为8.7、9.9和10.8℃,完成发育所需的有效积温分别为176.0、189.6和331.8日·度。绿眼赛茧蜂在我国草地螟发生危害区可发生2~7代/年。     

Effect of lidocaine on the minimum alveolar concentration of isoflurane in dogs

OBJECTIVE: To determine the influence of a low-dose constant rate infusion (LCRI; 50 microg kg(-1) minute(-1)) and high-dose CRI (HCRI; 200 microg kg(-1) minute(-1)) lidocaine infusion on the minimum alveolar concentration (MAC) of isoflurane (I) in dogs. STUDY DESIGN: Prospective experimental study. ANIMALS: Ten mongrel dogs (four females, six males), weighing 20-26.3 kg. METHODS: Dogs were anesthetized with I in oxygen and their lungs mechanically ventilated. Baseline MAC was determined using mechanical or electrical stimuli. Lidocaine (2 mg kg(-1) IV) was administered over 3 minutes, followed by the LCRI and MAC determination commenced 30 minutes later. Once MAC was determined following LCRI, the lidocaine infusion was stopped for 30 minutes. A second bolus of lidocaine (2 mg kg(-1), IV) was administered, followed by the HCRI and MAC re-determined. Concentrations of lidocaine and its metabolites were measured at end-tidal I concentrations immediately above and below MAC. Heart rates and blood pressures were measured. RESULTS: Minimum alveolar concentration of I was 1.34 +/- 0.11 (%; mean +/- SD) for both types of stimulus. The LCRI significantly reduced MAC to 1.09 +/- 0.13 (18.7% reduction) and HCRI to 0.76 +/- 0.10 (43.3% reduction). Plasma concentrations (ng mL(-1), median; value below and above MAC, respectively) for LCRI were: lidocaine, 1465 and 1537; glycinexylidide (GX), 111 and 181; monoethylglycinexylidide (MEGX), 180 and 471 and for HCRI were: lidocaine, 4350 and 4691; GX, 784 and 862; MEGX, 714 and 710. Blood pressure was significantly increased at 30 minutes after high dose infusion. CONCLUSION AND CLINICAL RELEVANCE: Lidocaine infusions reduced the MAC of I in a dose-dependent manner and did not induce clinically significant changes on heart rate or blood pressure.     

大小年经营竹林与花年经营竹林笋,竹产量对比试验

大小年经营的毛竹林改制为花年竹林，花年经营的毛竹林平均笋产量比大小年经营的增加１５０．５９％，提高２．５倍，笋竹两项经济收入比大小年经营的毛竹林增加１９０．３％，提高２．９倍。     

在几个新标准物理量的表示法及其应用上的若干问题辨析

近几年出版的化学及其相关学科的一些书刊中,在对新标准物理量的表示法及其具体应用上,常出现一些不妥之处,甚至出现错误。其中有些问题直接关系到学科发展和科学理论的先进性和科学性,因此,有必要予以澄清。本文将对上述存在问题进行辨析,并提出修正意见,供同事们作参考。     

17—4PHMo钢的热处理与电化学腐蚀关系的研究

本文讨论了17—4PHMo(OCr17Ni4Cu4Mo2Nb)钢在含1.8％H_2SO_4和4.5％NaCl的溶液中电化学腐蚀行为。试验表明:经正常热处理的试样,在含Cl~-和H~+的溶液中能生成稳定的钝化膜,这种钝化膜只有当金属阳极电位高于20毫伏时才能被击穿。同时,由于Epp值相对较正,即使钝化膜被击穿而产生局部的点蚀,也能重新钝化,恢复完整的钝化膜。本文还讨论了钢热处理后的显微组织,也讨论了热处理工艺与电化学性能之间的关系,从而阐明该钢在较高NaCl含量的酸性溶液中不易产生点腐蚀破坏。     

蒜薹贮存期病害发生规律及防治技术研究

恒温冷库贮存蒜薹常发病霉烂。经分离鉴定有12种病原菌,其中灰霉菌是主要致病菌。菌源主要来自田间,其次是库房带菌。蒜薹采收质量差、贮藏期间温、湿度和气体成分不合理,导致蒜薹生理活动失调,失去抗病能力,造成灰霉病蔓延。田间喷施速克灵、多菌灵等药剂,使蒜薹带药入库;蒜薹入库预冷期,用特克多、扑海因、速克灵、植物激素浸蘸薹尾和薹基部都有良好的防病保鲜效果。     

三元混配吡啶并[3,2-f][1,7]邻菲咯啉-Cu2+-5′-三磷酸尿苷配合物稳定性研究

用pH电位滴定法研究了三元混配吡啶并[3，2-f][1,7]邻菲咯啉-Cu^2 -5′-三磷酸尿苷[Cu(pdphen)(UTP)^2-]配合物在水以及φ为30%，50%的二氧六环-水溶液中的稳定性（25℃，0.100mol/LNaClO4)，将三元配合物与相关的二元配合物Cu(UTP)^2-的稳定性比较，发现三元配合物分子内存在着额外的稳定化作用，这可能主要归因于分子内配体UTP^4-磷酸基团上氧负离子与配体pdphen芳环间的σ-π协同作用以及UTP^4-尿嘧啶碱基与配体pdphen芳环间的堆积作用，用紫外差示光谱法确证了芳环间的堆积作用。     

种子介电分选技术研究现状及发展潜力

该文介绍了种子介电分选技术的产生和发展过程；与传统选种技术相比，其所具有的优越性；以及国内外对介电分选技术的理论研究及设备研制的状况。通过纵向和横向的对比分析，肯定该技术的发展潜力，并就现存的问题及以后的研究方向提出一些探讨性的意见。     

水稻新品种镇稻10号的丰产稳产性及其利用

[目的]为水稻生产中合理利用镇稻10号提供依据。[方法]以2004~2005年度江苏省水稻新品种区域试验和生产试验结果为分析资料,采用高稳系数法,结合产量变异系数和适应度,对镇稻10号和对照武运粳7号进行比较。[结果]在2004~2005年区域试验、2005~2006年区域试验和生产试验中,镇稻10号的平均产量分别为9 008.258、655.008、319.15 kg/hm2,分别比对照增产3.27%、3.59%、5.37%;高稳系数分别为90.56%、86.33%和70.41%,均大于对照;产量变异系数分别为3.53%、8.33%、26.50%,均小于对照;适应度分别为57.14%、71.43%、75.00%,均大于对照。[结论]镇稻10号是一个高产稳产、丰产性好的晚粳稻新品种,具有较好的广适性,增产潜力大,适宜在沿江和苏南等中高产地种植。