Effects of the Mechanism of Receptor-Mediated Gene Expression on the Shape of the Dose-Response Curve

A mathematical model of receptor-mediated gene expression that includes receptor binding of natural and xenobiotic ligands, protein synthesis and degradation, and metabolism of the xenobiotic ligand was created to identify the determinants of the shape of the dose-response profile. Values of the model's parameters were varied to reflect alternative mechanisms of expression of the protein. These assumptions had dramatic effects on the computed response to a bolus dose of the xenobiotic ligand. If all processes in the model exhibit hyperbolic kinetics, the dose-response curves can appear sigmoidal but actually be linear with a positive slope at low doses. The slope of the curve only approached zero at low dose, indicative of a threshold for response, if binding of the xenobiotic ligand to the receptor exhibited positive cooperativity (ligand binding at one site increases the affinity for ligand at another binding site on the receptor). Positive cooperativity in the rate-limiting step of protein synthesis produced dose-response curves which were "U-shaped" at low doses, also indicative of a threshold. Positive cooperativity in the metabolism of the xenobiotic ligand produced dose-response curves that increased more rapidly than linearly with increasing dose. The model illustrates the fact that response cannot be predicted from qualitative mechanistic arguments alone; any assessment of risk to health from xenobiotic chemicals must be based on a detailed quantitative examination of the kinetic behavior of each chemical species individually.     

CAI函数图形发生器FGG的设计与实现

介绍在Ｗｉｎｄｏｗｓ环境下用ＢｏｒｌａｎｄＣ＋＋３．１开发的通用函数图形发生器的结构和功能，讨论了实现中的表达式求值算法和图形生成算法。ＦＧＧ的主要特点是，对输入的任意一元、二元函数表达式可直接生成对应的二维和三维图形。ＦＧＧ作为ＣＡＩ写作工具的支撑软件，可用于ＣＡＩ课件的开发及演示。     

略论旅游服务语言艺术

旅游服务语言是旅游工作者与旅游者之间为了表达愿望、交流感情、进行交往和解决各种问题而使用的一种媒介和工具。它具有规范性与灵活性统一、文明性和职业性等个性特征。在运用旅游服务语言时应充分关注宾客的个性特点、突出语言的针对性 ,应充分发挥无声语言的作用 ,增强语言的感染力 ,同时用词规范准确得体、通俗易懂 ,并根据语境调节语速语调 ,灵活运用多种表现手法 ,方能取得客我双方满意的效果     

屈原骚怨心境剖析

屈原骚怨心境的生成源于"信而见疑,忠而被谤"的处境,其"骚(忧)"有二:得不到国君信任之"忧",找不到志同道合者之"忧";其"怨"亦有二:楚王昏聩之"怨",群小谗陷之"怨"。诗人以神话思维方式,运用多种艺术手段抒写内心的骚怨情怀,这种思维方式的运用与诗人所生活的楚地盛行巫风、巫文化有关。骚怨心境驱使诗人进行审美创造活动,诗人的骚怨心境在审美创造活动中得以宣泄。     

译论固可立 译笔价更高——翻译理论与实践矛盾浅析

该文通过对若干翻译教材和翻译论著中一些翻译实例的分析,揭示了这样一个现象:无论是翻译教材还是论著,在理论论述上都颇成一体,但著者在翻译实践上均暴露出功力不足或细心不够,故而,这些教材和论著的指导作用无论在技术上还是在学风上都大打折扣.笔者认为,翻译理论固然重要,但良好的翻译质量则是翻译研究的灵魂所在,也是翻译课程质量的保证所在.即所谓"译论固可立,译笔价更高".     

论新闻写作表达阶段的分析

在新闻写作系统中,表达具有十分重要的地位和作用.新闻写作的表达阶段,首先要分析鉴别新闻事实的真实性;其次是分析新闻事实的信息价值;第三是在事实分析的基础上,提炼出新颖、深刻的主题;最后是分析"口径"和"基调"、"时机"和"角度",有效地实现报道动机和报道效果的和谐统一.这样,新闻才能最充分地发挥其功能,实现其价值.     

The Effects of the Facial Expression of Beneficiaries in Charity Appeals and Psychological Involvement on Donation Intentions

To increase the effectiveness of fundraising campaigns, many human‐need charities include pictures of beneficiaries in their ads. However, it is unclear when and why the facial expression of these beneficiaries (sad versus happy) may influence the effectiveness of charity ads. To answer these questions, an experiment was conducted to investigate the effect of the facial expression on donation intentions, while considering the moderating role of psychological involvement with charities. It found that psychological involvement with charities moderated the impact of the facial expression on donation intentions in that seeing a picture of a sad versus happy person increased intentions to give among participants with lower levels of psychological involvement, whereas the reverse was true for highly involved participants. The moderating effect of psychological involvement was fully explained by the perceived efficacy of one's donation. The findings not only contribute to our understanding of the effect of the facial expression of people pictured in charity appeals on donation behavior, but also suggest that nonprofits should tailor their ads to target potential donors with various levels of psychological involvement with charities.     

试论艾略特《荒原》中的“非个人化”理论

文章结合艾略特的＂非个人化＂理论对其诗作《荒原》进行解读,通过对这首诗的分析来阐释该理论的内涵,＂非个人化＂理论在此诗中得到了成功的运用,其中关于该理论的重要表达手法也贯穿其中。     

试论老舍小说语言的三大系统

老舍先生的小说语言之所以风格鲜明，魅力独特，是因为它是作家在一整套文学语言理论的指导下自觉实践的结果。老舍先生的小说语言形成了三大独特的系统：字、词、句、段、篇、章的表达系统，辩证统一的审美系统，以“心”立“言”、以“言”造“境”的语境系统。     

理据·内部形式·词义

＂理据＂既可指整个语言的理据性（广义的理据）,也可指具体语词的语音和语义最初结合的动因（狭义的理据）。理据性和任意性是共同支配语言的两条同等重要的原则。内部形式是居于复合体内部的微结构,要考察它就需要把它转换成内部形式的展现形式。复合词以其内部形式提供出比单纯词更加丰富的潜台词信息。词有词义,也必有理据,复合词还有内部形式,所以仅仅注意词本身的音义（外部形式）是不够的,只有将此三者作通盘的考虑,厘清它们之间的关系,才可以做出完整的全面的考察。理据和内部形式呈因果关系。内部形式是词义的承载形式,内部形式属于物质范畴,而词义属于意念范畴。理据不仅可以破解不直观内部形式,而且还可以深化对直观内部形式的认识。