黄丘一区水平梯田田坎侧坡的稳定性研究

水平梯田是黄土丘陵沟壑区主要的坡面治理工程,也是主要的基本农田。水平梯田的田坎侧坡是水平梯田的重要组成部分,它不仅影响水平梯田的稳定,而且影响田坎占地的多少。采用现场调查与定位观测相结合的方法搜集典型流域田坎高与田坎侧坡资料,通过稳定统计分析,得出黄土丘陵沟壑区第一副区水平梯田(单式埂)田坎侧坡与田坎高的稳定性关系回归于二次多项式函数或指数函数,回归方程为二次多项式函数或指数函数的结论。     

局部供应硝酸盐诱导玉米侧根生长的基因型差异

以两个玉米(Zea.mays.L.)自交系478和Wu312为研究材料,采用琼脂培养方法,研究局部供应不同浓度的硝酸盐(NO3-)对侧根生长的影响。结果表明,根系局部供应0.5mmol/L硝酸盐,可以促进两个基因型相应部位的侧根长度,对478的促进效果显著高于Wu312。在双层局部供应0.5mmol/L硝酸盐时,能够刺激两个层次478局部侧根伸长,而Wu312只在上层表现出促进作用。多浓度试验结果表明,在0.5～25mmol/L范围内,局部供应硝酸盐均能在478上表现促进效果。而在Wu312上,当局部硝酸盐浓度超过5mmol/L,刺激作用消失。在低浓度范围内,局部供氮不影响侧根。当局部供应的硝酸盐浓度超过5mmol/L时,Wu312的侧根数量急剧下降,超过15mmol/L后,478的侧根数量开始下降。478侧根对局部硝酸盐刺激的响应能力显著高于Wu312。     

温湿度条件与凯特两性花百分率关系的研究

为探索温湿度条件与果两性花百分率的关系,以"凯特"为研究对象,以两性花百分率为方程依变量,55个温湿度因子为自变量,应用数理统计方法分析了两者的相关关系。结果表明:"凯特"是两性花百分率较高的品种,随花期延后,温度增高,两性花百分率提高;花器官主要分化期自开花前30d开始至花前1d结束;两性花百分率受花器官主要分化期日均高温、日均温、日均低温和日积温的影响,四者的影响规律相似。花前21~30d、11~15d、1~5d的日均高温、日均温、日均低温、日积温以及花前6~10d的日均温、日均低温、日积温与两性花百分率为直线相关,随温度增高,两性花百分率提高;花前16~20d的日均高温、日均温、日均低温、日积温以及花前6~10d的日均高温与两性花百分率为多项式线性相关,温度由低升高两性花百分率提高,但超过一定温度则降低。花器官主要分化期全程的日均空气湿度均对两性花百分率有影响,但最敏感时期为花前11~20d。由此认为,"凯特"小花子房退化与花器官主要分化期所处的温湿度环境密切相关,适当高的温湿度有利于子房的发育和两性花百分率的提高。     

FBW7 inhibits ox-LDL-induced granulosa cell apoptosis by promoting NOX1 degradation

AIM To investigate the effect of F-box and WD repeat domain containing protein 7 （FBW7） on the injury of granulosa cells （GCs） induced by oxidized low-density lipopretion （ox-LDL） stimulation and its potential mechanism. METHODS The GCs isolated from women of reproductive age with different obesity levels, the GCs isolated from high fatty diet （HFD）-fed rats, and the ox-LDL-treated rat GCs were collected, and the expression of FBW7 was detected by Western blot. After the rat GCs were infected with adenovirus encoding FBW7 （Ad-FBW7）, the cells were treated with ox-LDL （80 mg/L） for 48 h, and then the cell viability, apoptosis, NADPH oxidase （NOX） activity and the key subunit proteins of NOX were detected by CCK-8 assay, Annexin V/PI staining, lucigenin chemiluminescence and Western blot, respectively. The effect of FBW7 over-expression on NOX1 degradation was evaluated by cycloheximide （CHX） chase assay. RESULTS The expression of FBW7 was lower in the GCs isolated from obese women of reproductive age, the GCs isolated from HFD-fed rats, and the ox-LDL-treated rat GCs （P<0.05）. Over-expression of FBW7 inhibited ox-LDL-induced injury of GCs, NOX activity, and NOX1 expression （P<0.05）. The results of CHX chase assay showed that over-expression of FBW7 accelerated the degradation of NOX1 protein under ox-LDL condition （P<0.05）. CONCLUSION Over-expression of FBW7 reduces ox-LDL-induced injury of GCs by accelerating NOX1 degradation and then weakening NOX activity.     

水稻无侧根突变体RM109的氧化还原代谢

比较无侧根突变体RM1 0 9和原品种大力根琥珀酸脱氢酶 (SDH)的活性发现 :RM1 0 9为大力的 60 %～ 70 % ,还原剂处理下大力的SDH活性显著增加 ,而RM1 0 9无变化。RM1 0 9的该酶受单显性基因控制。RM1 0 9对NAA、TIBA的耐性明显增加 ,对H2 O2 的耐性明显下降。结果表明 :氧化还原代谢有突变     

水稻无侧根突变体RM109冠根的解剖学观察

对水稻无侧根突变体RM1 0 9与原品种大力 (OryzasativaL .,cv .Oochikara)的冠根组织形态进行比较 ,结果表明 ,大力品种可观察到侧根原基及侧根 ,而RM1 0 9均无 ;RM1 0 9的原生木质部间中柱鞘细胞数目减少 ,为大力的 77% ;后生木质部导管数增加 ,其导管I的数量为大力的 1 4 9% ,其导管Ⅱ的数量为大力的 3 2 1 % ,且导管排列散乱。推测其原因在于根尖生长点细胞分化异常和IAA合成能力低下     

Surface distribution of pyrethroids following topical application to veterinary species: Implications for lateral transport

Pyrethroids like permethrin have been used as topical formulations for their ectoparasiticidal effects since the 1970s. There are numerous efficacy studies in dogs and livestock animals that indicate a fast spread of pyrethroids after topical administration onto rather confined areas of the skin. Some studies correlate the efficacy against ticks, fleas or lice with concentrations of pyrethroids in hair and, less frequently, stratum corneum samples. It is often stated that lateral transport is responsible for the distribution of the pyrethroids over the body surface. With this review, we attempt to demonstrate evidence for lateral transport of pyrethroids after topical administration in dogs, cattle and sheep and to present data gaps that should be addressed in follow‐up studies.     

小管出流灌溉技术的研究（Ⅱ）──系统的设计方法问题

小管出流灌溉系统的设计方法步骤与滴灌系统大致相同。但由于小管灌水器的出流量比滴头大得多，系统设计的许多问题又具有特殊性。本文论述了设计均匀度的确定，适宜毛管直径和长度的确定，以及田间管网水力学计算等问题。［关键词］     

滴灌条播作物毛管水力设计方法探讨

研究毛管水力设计历来为人们所重视,但从目前资料来看,正确运用水力学原理,探讨改进设计方法,对提高设计精度,充分发挥滴灌效益,仍有实际意义。毛管以下滴灌设备件小、用量大,其投资占全系统的40％～50％。尤其是滴灌条播作物(如葡萄,黄瓜等),因种植密度大,毛管设计优劣与系统运行,灌溉质量,费用高低等关系尤为密切。考虑到采用微管滴头,按等量出流设计的毛管计算比较繁锁,故本文将通过对实际计算方案讨论,阐明多孔出流条件下的一些设计参数取值、算法、给出简化水力计算公式及其设计应用方法,供设计者参考。