You are what you eat: native versus exotic Crotalaria species (Fabaceae) as host plants of the Ornate Bella Moth,Utetheisa ornatrix (Lepidoptera: Erebidae: Arctiinae)

Crotalaria plants and Utetheisa ornatrix are closely linked to each other: the larvae destroy the seeds, while the moth depends on hostplants for alkaloids. To better understand the ongoing co-evolution, the present study examines how native hostplants compare to exotic ones. Leaf-feeding on Crotalaria pumila, C. rotundifolia, and C. incana, native to the moth’s range, led to faster larval development than on the exotic C. lanceolata, C. spectabilis, and C. pallida. Seed-feeding on all species of Crotalaria led to accelerated larval development and a resultant larger adult moth, and correlates with a higher nitrogen content in the plant tissues. These results add a novel dimension to the previous studies of reproductive biology of this model organism. In controlled settings, mature larvae showed preference for leaves of C. spectabilis over those of other species, perhaps due to the higher alkaloid content. Differences in morphology and phenology of Crotalaria determine the ecology of U. ornatrix populations in Florida. The introduction of novel hostplants, on which U. ornatrix can have a significant negative effect and which are of concern to humans as invasive toxic weeds, has greatly expanded the niche occupied by this moth. Possible co-evolution of Utetheisa sensu lato and plant defences in the genus Crotalaria is discussed.     

Mating behaviour and maternal care in the tropical savanna funnel-web spider Aglaoctenus lagotis Holmberg (Araneae: Lycosidae)

Despite their abundance and diversity, Neotropical spiders have been the subject of relatively few studies of behavioural ecology. The sexual behaviour and maternal care of the spider Aglaoctenus lagotis (Lycosidae) is described here. We performed experimental manipulations to test the hypothesis that males are attracted by female cues in the web. Two predictions were tested: (a) webs used by a virgin female will attract more males than webs used by an inseminated female; (b) the main cue in the web is chemical, so webs recently used by virgin females will attract more males than those that are not recently used. Additionally, we tested the hypothesis that maternal care increases offspring survivorship. Results showed that males are attracted by recently used webs (z = 0.0015; p = 0.037; z-test) and webs of virgin females (z = 0.041; p = 0.036, z-test). Male sexual behaviour presented three different categories: court, pre-mate and mate. After the mating, the females built a cocoon that was transported adhered to the spinnerets and held by the last pair of legs. After the hatching of the eggs, the young migrated to the dorsal region of the mother's body for 5 days. During maternal care the mother eliminates a yellowish drop from its oral cavity, which is collected by the young. During the development of the young until adulthood, the offspring that have their mother present in the first stages of life have greater survival compared with those without maternal care. Our results make it possible to perform comparative analyses between a South American Lycosidae species and other species distributed worldwide.     

不同放牧强度下天然沙质草场植物群落分异特征及沙漠化发生机理试验研究

本文通过在科尔沁沙地沙质天然草场进行连续牧压梯度试验，主要得出如下结论：随着放牧强度的增加，植被盖度，地下生物量迅速下降，连续强度牧压下沙漠化在短期内（３～７个月）强烈发展；随着牧压的增加，地下生物量与地上生物量的比值呈上升趋势，土壤含水量也上升；放牧造成的沙漠化在初期阶段相对容易治理。     

高师化学实验绿色化问题的研究

化学实验教学中使用的药品种类繁多、性能复杂,常常给环境带来负面作用.已经查明现行高师化学教学实验存在一系列的环境污染问题,对此遵循绿色化学的提出12项基本原则分别对环境友好实验材料的使用、防止有毒物质的泄露等问题等进行了研究和实践,通过化学实验课程绿色化问题的研究性学习取得了绿色化学实验和绿色化学教育的双赢.     

一株好氧反硝化菌的反硝化性能研究

选用四因素三水平L9(34)正交试验表设计实验,研究碳源、CODCr/N、溶解氧以及pH值对菌株tsuruhatensis戴尔福特菌好氧反硝化性能的影响,并对该菌株利用发酵罐进行扩大培养.实验结果表明,此菌株为一株高效的好氧反硝化菌.     

无机化学实验教学中过程与方法目标的实施

实验是化学、生物等理科学科的重要组成部分,实验教学是提高学生科学素养与综合能力的最佳途径。本文介绍了在无机化学实验教学中实施过程与方法目标的分解与细化,使相对粗放的实验教学转化为量化教学的改革探讨。     

线性滑动光滑法对非线性数据处理结果的影响

利用线性滑动方法中的一阶五点公式、处理了一组物理实验数据。结果对比分析表明,对物理实验中的原始数据先经过必要的数据预处理,能提高实验数据处理结果的精度,增强物理实验的验证效果。     

物理实验室信息化管理系统的研究与开发

利用Visual Fox Pro数据库程序设计语言，研究了物理实验室信息化管理系统的设计方法，并介绍了该系统的主要功能及特点。     

试探Reactor动力学系统在物理演示实验中的应用

在物理课堂中利用计算机仿真演示实验进行辅助教学一直受到许多关注与研究．已有各种技术被应用到进行物理仿真演示的多媒体教学软件的开发中．本文论述了如何利用3dsMax中的Reactor动力学系统这一新技术进行物理力学现象的仿真演示，这种技术具有不需编程、创作快捷、形象直观且容易学习、实现交互性好等特点．