主伐对森林景观结构和空间分布格局影响的研究

本文用不同尺度分析了采伐对森林景观的影响。通过对景观组成单元的类型、总体景观比例随海拔梯度的分布格局、景观内各组份水平分布的隔离度等比较表明，采伐后自然重建的景观与原生景观无显著差异，森林景观对采伐干扰具有渐进稳定性。各景观单元均属聚集性分布。景观内部结构的多样性、均匀度有一定提高，景观优势度有所降低。采伐使景观单元破碎化，出现重组现象。采伐引发的景观单元转移概率因类型不同而异；松栎混交林景观单元在其生态区位内稳定性强，对采伐有负反馈效应；华山松为优势的景观单元采伐后明显扩大，以铁杉为主的景观单元也有类似情况；弱度干扰的红桦、云、冷杉景观单元结构稳定并有所扩展。     

代森锰锌35%水悬浮剂制备

对代森锰锌35%水悬浮剂配方进行了研究。通过流点法缩小润湿分散剂的选择范围,对润湿分散剂、增稠剂等助剂的品种及用量进行了研究。通过大量的复配试验确定了最佳配方:原药35%、润湿分散剂8.5%、增稠剂0.25%、防冻剂4%,消泡剂1%、稳定剂1.5%,去离子水补至100%。     

油菜菌核病生防芽孢杆菌的分离鉴定及其脂肽化合物分析

采用平板拮抗筛选,分别从西藏日喀则地区和拉萨地区杂草根围土壤中筛选到2个对油菜菌核病菌有显著拮抗活性的芽孢杆菌菌株RJGP16和YBWC43。通过生理生化鉴定、16S rDNA序列分析和BOX-PCR指纹图谱分析,鉴定菌株RJGP16为萎缩芽孢杆菌Bacillus atrophaeus, 菌株YBWC43为解淀粉芽孢杆菌Bacillus amyloliquefaciens。离体叶片试验结果显示,菌株RJGP16和YBWC43对油菜菌核病菌防治效果分别为50.24%和100.00%。脂肽化合物种类分析显示,菌株RJGP16产生脂肽化合物表面活性素和芬枯草菌素,菌株YBWC43产生杆菌霉素D和芬枯草菌素。表明菌株RJGP16和YBWC43对油菜菌核病的防治效果与其产生的脂肽化合物有关。     

An Octopus-Derived Peptide with Antidiuretic Activity in Rats

Discovering new drug candidates with high efficacy and few side effects is a major challenge in new drug development. The two evolutionarily related peptides oxytocin (OXT) and arginine vasopressin (AVP) are known to be associated with a variety of physiological and psychological processes via the association of OXT with three types of AVP receptors. Over decades, many synthetic analogs of these peptides have been designed and tested for therapeutic applications; however, only a few studies of their natural analogs have been performed. In this study, we investigated the bioactivity and usefulness of two natural OXT/AVP analogs that originate from the marine invertebrate Octopus vulgaris, named octopressin (OTP) and cephalotocin (CPT). By measuring the intracellular Ca²⁺ or cyclic AMP increase in each OXT/AVP receptor subtype–overexpressing cell, we found that CPT, but not OTP, acts as a selective agonist of human AVP type 1b and 2 receptors. This behavior is reminiscent of desmopressin, the most widely prescribed antidiuretic drug in the world. Similar to the case for desmopressin, a single intravenous tail injection of CPT into Sprague-Dawley rats reduced urine output and increased urinary osmolality. In conclusion, we suggest that CPT has a significant antidiuretic effect and that CPT might be beneficial for treating urological conditions such as nocturia, enuresis, and diabetes insipidus.     

10个小麦品种（材料）对麦长管蚜的室内苗期抗蚜性*

［目的］ 明确不同小麦品种对麦长管蚜(Sitobion avenae)的室内苗期抗性。［方法］ 在温室内采用每株小麦接种1头蚜虫的方法,测定了麦长管蚜在来源于3个国家的10个小麦品种上的发育历期（DD）、相对日均体重增长量（MRGR）和成虫日均产仔数（Rm）,以此来确定不同小麦品种（材料）的抗蚜性。［结果］ 应用多元方差分析,多目标综合判别及聚类分析等方法分析表明,麦长管蚜在‘Ww2730’、‘98 10 30’、‘Astron’上的适应性最差,这几个品种对其抗性最好,是可以利用的抗性品种（材料）;‘98 10 35’、‘98 10 32’次之;‘Batis’对麦长管蚜的适应性最好,抗性最差;‘186Tm’,‘Xanthus’,‘Amigo’对麦长管蚜适应性较好,与作为对照的‘小偃 22’一样,抗性处在中间水平。［结论］ 研究结果可以为进一步的抗蚜育种提供依据。     

中国潜在产出测算实证研究

在对中国潜在产出测算研究状况进行评介的基础上,分别使用H-P滤波法和生产函数法估算了中国1978—2004年间的潜在产出、产出缺口和潜在产出增长率。结果表明:(1)1978—2004年间,中国的产出缺口出现了波动水平正负交替的周期情形;(2)1995年以前产出缺口的波动幅度比较剧烈且较为频繁,1996年特别是1999年以后产出缺口的变化较为平缓;(3)1997年以后,虽然经济的增长率保持较高的水平,但是生产要素的实际利用水平却逐渐降低;(4)生产函数法得到的结果基本客观的反映了改革开放后,中国开始从计划经济向市场经济过渡到市场经济初步建立这一时期的生产要素使用情况。(5)根据H-P滤波法和生产函数法估算的潜在产出,得到1978—2004年间的平均潜在产出增长率分别为9.54%和9.67%。根据估计结果,在今后几年,通过适当的宏观调控,把中国的经济增长率稳定在8%～9%可能是一个较好的选择。     

利用贴牌水培法快速鉴定稗草对二氯喹啉酸的抗药性水平

本文通过室内贴牌水培法及整株法,快速鉴定并验证了2013年采自湖南省不同地区稻田的50个稗草生物型对二氯喹啉酸的抗药性,试验结果表明:贴牌水培法所用的二氯喹啉酸甄别剂量为80mg/L;稗草死亡率越低,其抗性倍数(resistance factor,RF)越高,其中死亡率为0时,整株法测定的RF值高达896.07~1 209.38;贴牌水培法测定的稗草样本对二氯喹啉酸的ED50远低于整株法,但两种方法得到的不同稗草生物型对二氯喹啉酸的抗性水平趋势高度吻合。笔者认为以贴牌水培法测定的死亡率小于40%的稗草样本对二氯喹啉酸的抗性风险较高,值得深入研究。     

Actions of quinolizidine alkaloids on Periplaneta americana nicotinic acetylcholine receptors

BACKGROUND: Botanical insecticides do not play a major role as crop protectants, but they are beneficial in some applications. The authors investigated the actions of naturally occurring alkaloids on insect nicotinic acetylcholine (ACh) receptors (nAChRs) by evaluating their abilities to inhibit specific binding of [³H]imidacloprid (IMI) to nerve‐cord membranes from Periplaneta americana L. Two alkaloids were also tested for their actions on nAChRs expressed by cockroach neurons using patch‐clamp electrophysiology. RESULTS: Four natural quinolizidine alkaloids (matrine, sophocarpine, cytisine and aloperine) exhibited more than 50% inhibition of [³H]IMI binding at 10 µM , although other compounds were found to have no or low inhibitory activity. The rank order of potency based on concentration–inhibition curves was cytisine > sophocarpine ≥ aloperine ≥ matrine. Patch‐clamp analysis indicated that sophocarpine and aloperine were not agonists of nAChRs expressed in P. americana neurons, yet, at 10 µM , aloperine, but not sophocarpine, suppressed ACh‐induced inward currents significantly. CONCLUSION: Three of the four natural alkaloids tested possess structural moieties that are necessary for interaction with P. americana nAChRs. Aloperine, which possesses a unique structure and showed a distinctive dose–response curve, was found to act as an antagonist. Appropriate modifications of these alkaloids might result in novel insecticidal nAChR ligands. Copyright © 2008 Society of Chemical Industry     

油菜冻害原因及其预防措施

对油菜冻害发生的症状、原因进行了分析,并提出了相应的预防措施。     

8种杀螨剂对苹果树红蜘蛛田间防效评价

对8种不同作用机理杀螨剂防治苹果树红蜘蛛的效果进行了田间试验。结果表明：三唑锡、炔螨特、哒螨灵、阿维菌素、唑螨酯、螺螨酯、双甲脒、甲氰菊酯均是防治苹果树红蜘蛛的有效药剂,以螺螨酯的总体防效最好。