Comparative study of the karyotypes of two Egyptian species of bats,Taphozous perforatus andTaphozous nudiventris (Chiroptera: Mammalia)

A detailed karyotypic analysis of two Egyptian species of bats,Taphozous perforatus andTaphozous nudiventris, was made on the basis of conventional data and G-band patterns. No detectable karyotypic difference was found between the two species (2n=42, F.N. 64). By comparison of G-band patterns, some differences between the two species were seen in the corresponding autosomal pairs. These results are reported for the first time in Egypt.     

影响牦牛初生重因素的系统分析

分析了影响牦牛初生重的六个因素和众多因子，母牦牛的产犊季节、牦牛的胎次、犊牛的性别对牦牛初生重影响最大；母牛的年龄、营养情况对初生重影响次之；放牧管理水平对初生重影响最小。     

铅溴络合物极谱吸附波的研究

本文研究了铅溴络合物在高氯酸－磷酸－草酸介质中的极谱行为。确定底液组成为５％ＮａＢｒ－１１％ＨＣｌＯ４－５％Ｈ３ＰＯ４－０．８％Ｈ２Ｃ２Ｏ４。工作曲线线性范围为０－１５０μｇ／５０ｍｌ检测下限达０．０１μｇ／ｍｌ体系选择性好，应用于实际样品的测定，获得满意结果。     

Indoxyl derivatives of drug metabolites

Summary Indoxyl derivatives were detected as minor products among the urinary metabolites of two trial drugs, a benzodiazepine (GP 55 129) and a benzophenone (CGP 11 952). Their structures were elucidated by NMR and mass spectroscopy. Presumably, metabolites containing potential aldehyde functions react spontaneously with endogenous indoxyl. Such derivatives have not hitherto been encountered in drug metabolism.     

The melatonin rhythm: both a clock and a calendar

The paper briefly reviews the data which shows that the circadian production and secretion of melatonin by the pineal gland can impart both daily, i.e., clock, and seasonal, i.e., calendar, information to the organism. The paper summarizes the 3 patterns of nocturnal melatonin production that have been described. Clearly, regardless of the pattern of nocturnal melatonin production a particular species normally displays, the duration of nightime elevated melatonin is proportional to the duration of the night length. Since daylength under natural conditions changes daily the melatonin rhythm, which adjusts to the photoperiod sends time of year information to the organism. The melatonin receptors which subserve the clock message sent by the pineal gland in the form of a melatonin cycle may reside in the biological clock itself, namely, the suprachiasmatic nuclei (SCN). The melatonin receptors that mediate seasonal changes in reproductive physiology are presumably those that are located on the pars tuberalis cells of the anterior pituitary gland. Besides these receptors which likely mediate clock and calendar information, melatonin receptors have been described in other organs. Interestingly, the distribution of melatonin receptors is highly species-specific. Whereas the clock and calendar information that the melatonin cycle imparts to the organism relies on cell membrane receptors, a fact that is of some interest considering the high lipophilicity of melatonin, recent studies indicate that other functions of melatonin may require no receptor whatsoever.     

简支平行四边形底扁壳大挠度问题的准确解

本文将 S·Levy 在1949年解矩形板大挠度问题的双三角级数解法推广到平行四边形板和扁壳的情形。     

新世纪图书馆员社会角色转换研究综述

就近几年图书馆界关于新世纪馆员意识转换及社会角色转换等方面的研究进行了综述，指出新时期的馆员要实现自我社会角色的转换，首先是要明确转换的必要性，然后采取有效的策略逐步地、系统地推进转换，才能取得较好的效果。     

对当前机关辖区事业单位人事管理的思考

介绍了当前机关辖区事业单位的现状和特点，阐述了事业单位人事制度改革的重要性，并时今后事业单位在人事制度、分配制度和医疗保险制度等方面的改革及=L作重点进行了分析。     

证券投资基金持股的风险特征实证研究

使用股票的平均收益、CAPM风险测度(β值)和传统风险测度(标准差、偏度和峰度)对我国证券投资基金在2000～2002年期间的投资决策进行了实证分析．结果表明，在这3年中，基金的持股比重与股票的卢值具有不显著的相关性，而与股票的标准差、偏度和峰度之间的相关性则比较显著，这表明了基于个股属性的传统风险测度对基金经理的投资决策起着重要作用，而CAPM理论是否得到基金经理的广泛运用还有待于进一步论证．     

Sound communication inNezara viridula (L.) (Heteroptera: Pentatomidae): Further evidence that signal transmission is substrate-borne

We investigated the sound communication associated with mating inNezara viridula (L.) to clarify conflicting reports on the medium through which acoustic signals are borne. Recordings made from virgin pairs ofN. viridula during precopulatory and compulatory behaviour have revealed that signals transmitted as vibrations through the substrate are a more likely means of communication than signals transmitted by a radiation of sound pressure waves through the air (at least in Australian populations). We present evidence (additional to that already in the literature) that air-borne acoustics are an unlikely mechanism of sexual communication in this species. Specifically, the recorded pulse train patterns showed no consistency or repeatability in relation to different stages of mating behaviour. In contrast, frequency spectrograms of substrate-borne signals reveal repeatable patterns that do correspond with the stage of mating behaviour.