“大虫”“老虎”“老虫”的历时演变与共时分布

“大虫”“老虎”“老虫”都是对虎的代称,通过分析它们在历史文献中的用例,考察出了它们的历时演变顺序:虫/虎—毛虫—大虫—老虎—老虫,否定了“大虫”来源于避讳的说法。通过对比它们历时与共时层面的地域分布,探究了“大虫”“老虎”“老虫”在历史进程中的使用范围的变化,明确了三者在词汇构成中的地位,即“老虎”成为全民常用词,“大虫”和“老虫”成为地域性方言词。

两种菊酯农药防治榆紫叶甲试验

10%顺式氯氰菊酯乳油10～20ppm有效浓度防治榆紫叶甲的若虫和成虫试验,其杀虫效果都可达100%;而卵的室内试验死亡率依次为82.5%、83.9%.林间依次为68.5%、74.4%。20%氰戊菊酯乳油同样以10～20ppm进行试验,其若虫死亡率依次为95.0%、96.0%;对成虫依次为90.0%、98.4%;但对其卵无毒杀作用。

为什么锚头蚤总是杀不掉呢?

一、锚头蚤寄生鱼种后,发育过程可分为童虫、壮虫、老虫三种形态:1.童虫身体细小如成长的头发丝,且呈白色透明状,没有卵黄,肉眼需仔细观察才能辨别得出,一般长2~3 d后便可发育为壮虫。当童虫感染为主时可以在半月内连续两次杀虫。2.壮虫身体粗壮且透明,用手触摸可竖起,肉眼可以清楚看到有黑色肠管在蠕动,体后挂有一对绿色卵囊。当壮虫感染为主时,用药一次即可。

“书虫”老爸

我有一个“书虫”老爸。在我们家的一面墙上。有一个“藏宝地”。那就是老爸放他那些“宝贝书”的壁柜了。不知是从什么时候开始的，老爸只要一出门。或是下班回家的时候，就要买书。有一次，当妈妈看到爸爸又带回了本新杂志时。她开始唠叨起来：“哎!你说你成天买书往家拿．也没见你在哪儿发表过几篇文章。如果你还要买书的话，必须在一个月之内赚100元钱稿费。否则的话，不但不让你买书．而且要把你所有的书卖给收废品的!”可也就怪了，

我的“虫虫”老爸

你肯定知道我的“虫虫”——老爸吧!啥？不知道？那我就给你讲一讲他，麻烦你洗耳恭听哟!

Effects of Sublethal Doses of Chlorfluazuron on Ovarioles in the Common Cutworm, Spodoptera Litura （F.） （Lepidoptera： Noctuidae）

Chlorfluazuron is an insect growth regulator for controlling the major insect pests in crops. This paper describes the effects of sublethal doses （LD10：1.00 ng/larva; LD30：3.75 ng/larva） of chlorfluazuron on ovarioles during ovarian development and oogenesis of common cutworm, Spodoptera litura （F.）. It is a significant pest of cotton, tobacco and miscellaneous vegetables. The LDlo or LD3o was applied topically to the newly-ecdysed fifth-instars of S. litura under laboratory conditions. In controls, on 2nd day of adult emergence, the cell density in germarium was 1636 ± 9.17 nuclei/mm^2. It increased until 3rd day, i.e., 1829 ± 8.87 nuclei/mm^2 and decreased thereafter. In the LDloor LD-3o-treated insects, the patterns of the cell density was the same as in controls but values were significantly （P 〈 0.05） decreased in the LD10- and more in the LDa0-treated females compared with controls. In control, ovaries were normal type and had mature ova with an occasional one or two being absorbed. In LD10-treated females, ovaries had spaces in ovarioles and absorption of ova. In LD30-treated females, besides the spacing and absorption, sometimes only immature （germarium） ova were found.

Anti-aging properties of Ribes fasciculatum in Caenorhabditis elegans

The present study investigated the effects and underlying mechanism of ethylacetate fraction of Ribes fasciculatum （ERF） on the lifespan and stress tolerance using a Caenorhabditis elegans model. The longevity activity of ERF was determined by lifespan assay under normal culture condition. The survival rate of nematodes under various stress conditions was assessed to validate the effects of ERF on the stress tolerance. To determine the antioxidant potential of ERF, the superoxide dismutase （SOD） activities and intracellular reactive oxygen species （ROS） levels were investigated. The ERF-mediated change in SOD-3 expression was examined using GFP-expressing transgenic strain. The effects of ERF on the aging-related factors were investigated by reproduction assay and pharyngeal pumping assay. The intestinal lipofuscin levels of aged nematodes were also measured. The mechanistic studies were performed using selected mutant strains. Our results indicated that ERF showed potent lifespan extension effects on the wild-type nematode under both normal and various stress conditions. The ERF treatment also enhanced the activity and expression of superoxide dismutase （SOD） and attenuated the intracellular ROS levels. Moreover, ERF-fed nematodes showed decreased lipofuscin accumulation, indicating ERF might affect age-associated changes in C. elegans. The results of mechanistic studies indicated that there was no significant lifespan extension in ERF-treated daf-2, age-l, sir-2.1, and daf-16 null mutants, suggesting that they were involved in ERF-mediated lifespan regulation. In conclusion, R. fasciculatum confers increased longevity and stress resistance in C. elegans via SIR-2.1-mediated DAF-16 activation, dependent on the insulin/1GF signaling pathway.

Molecular mechanisms of dietary restriction in aging—insights from Caenorhabditis elegans research

Dietary restriction(DR) is one of the most robust environmental manipulations that not only extend life span but also delay the onset of age-related diseases in almost every species examined. Caenorhabditis elegans plays an important role in aging studies due to its simple life cycle, easy genetic manipulations and highly conserved genome. Recent studies have demonstrated that the beneficial effects of DR are mediated by the highly conserved transcription factors and signaling pathways in C. elegans. Here we review recent progress in the methodology and molecular mechanisms of DR using C. elegans as a model, as well as prospects for future research.

Copper ions influence the toxicity of β-amyloid(1-42) in a concen-tration-dependent manner in a Caenorhabditis elegans model of Alzheimer’s disease

β-amyloid (Aβ) and copper play important roles in the pathogenesis of Alzheimer’s disease (AD).However,the behavioral correlativity and molecular mechanisms of Aβ and copper toxicity have been investigated less often.In the present study,we investigated the interaction and toxicity of Aβ1-42 and copper in the Aβ1-42 transgenic Caenorhabditis elegans worm model CL2006.Our data show that the paralysis behavior of CL2006 worms significantly deteriorated after exposure to 10-3 mol L-1 copper ions.However,the paralysis behavior was dramatically attenuated with exposure to 10-4 mol L-1 copper ions.The exogenous copper treatment also partially changed the homeostatic balance of zinc,manganese,and iron.Our data suggest that the accumulation of reactive oxygen species (ROS) was responsible for the paralysis induced by Aβ and copper in CL2006.The ROS generation induced by Aβ and copper appear to be through sod-1,prdx-2,skn-1,hsp-60 and hsp-16.2 genes.