一类Holling功能性反应模型极限环的唯一性

考虑功能性反应的捕食-食饵模型这里y表示捕食者种群的密度,当a-（22）≠0时它具有线性密度制约,x表示食饵种群密度,当φ（x）≡ax/（1＋ωx）时称（1）为第二类功能性反应模型．文〔1〕研究了捕食者没有密度制约（对应于a_（22）=0）、食饵具有线性密度制约(对应于g（x）=b_1-a_(11)x）的Ⅱ类功能性反应模型（1）,得到了极限环存在性及唯一性的完整结论．最近文〔2〕在a_(22)≠O的条件下讨论了系统(1),得到了极限环的存在性与不存在性等福建省自然科学基金和国家自然科学基金资助项目（19371069号）．本文第一作者现为浙江大学访问学…     

工业固体废弃物的急性生物毒性研究

工业固体废弃物的急性生物毒性研究谢思琴,顾宗濂,周德智（中国科学院南京土壤研究所,南京２１０００８）Ａｃｕｔｅｂｉｏｔｏｘｉｃｉｔｙｏｆｉｎｄｕｓｔｒｉａｌｓｏｌｉｄｗａｓｔｅｓ￥．ＸｉｅＳｉｑｉｎ;ＧｕＺｏｎｇｌｉａｎａｎｄＺｈｏｕＤｅｚｈｉ（Ｉｎ...     

自然免耕下的稻田生态系统

自然免耕是一种新型的稻田耕作法,通过人为改变地表微地形,建立了一个适合水旱作物复种轮作,鱼、萍、鸭周年共生的稻田生态系统．自然免耕促进了土壤内、外环境的物质、能量和信息交换,水、热、气、肥谐调．并通过环境网络效应,强化了环境与生物区系间的缓冲－调节力．提高了土壤自调能力和土壤有序度．     

L．B－G．O对小鼠U_（14）宫颈癌细胞DNA合成和超微结构的影响

本实验合并应用枸杞有效成份和大蒜有效成份,作用于Ｕ_１４腹水型宫颈癌小鼠,腹腔注射第四天,发现一般状况改善,取腹水观察,癌细胞破损,ＤＮＡ、ＲＮＡ荧光染色强度减弱,有大量白细胞和巨噬细胞围绕;流式细胞分析Ｇ＿１期细胞堆积,超微结构显示胞质中线粒体肿胀,嵴破坏甚至中空,粗面内质网扩大、脱颗粒,肯定了其作用的效果。此因枸杞有效成分活化巨噬细胞与肿瘤细胞紧密结合而起到溶瘤作用,与大蒜有效成分直接杀伤而作用维持短暂结合起来,可大大提高抗癌作用。     

柏毒蛾核型多角体病毒的分离鉴定

柏毒蛾核型多角体病毒的分离鉴定李崇荣,彭辉银,周显明,陈新文,谢天恩（贵州省铜仁地区林科所,铜仁５５４３００）（中国科学院武汉病毒研究所,武汉４３００７１）（贵州省林业科学研究院,贵阳５５００１１）关键词柏毒蛾,核型多角体病毒柏毒蛾（Ｐａｒｏｃｅｎｅ...     

精子作载体的转基因鱼研究

本文报道了以精子为载体将美洲拟蝶抗冻蛋白基因导入罗非鱼卵,构建转基因鱼的方法,此法简单易行。斑点杂文和ＳｏｕｔｈｅｒｎＢｌｏｔ杂交结果表明,外源基因的整合率为１８．１％,与其它方法构建转基因鱼的外源基因整合率相近。     

检测特异性抗体分泌细胞(ASCs)的固相酶联免疫斑(ELISPOT)技术的建立

ＥＬＩＳＰＯＴ技术是目前国外评价疫苗免疫原性和免疫应答机理研究中最常使用的方法。本文用自制的ＮＣ膜２４孔板为固相支持物,建立了检测小鼠脾细胞中特异性ＡＳＣｓ的ＥＬＩＳＰＯＴ技术,在检测方法的特异性、结果的稳定性上均取得了满意的效果。并对该方法的某些实验条件进行了摸索。     

根瘤菌同工酶图谱分析和分类

利用聚丙烯酰胺凝胶电泳分析了９株根瘤菌酯酶及ＳＯＤ同工酶图谱,结果显示快生型根瘤菌与慢生型根瘤菌有明显区别,不仅根瘤菌种间有明显差别,而且菌株间也存在差异。Ｒｈｉｚｏｂｉｕｍｌｅｇｕｍｉｎｏｓａｒｕｍｂｉｏｖａｒｓｖｉｃｅａｅ和ｐｈａｓｅｏｌｉ具有相同的ＳＯＤ图谱和相似的酯酶图谱。快生型大豆根瘤菌的上述同工酶图谱不同于慢生型大豆根瘤菌和其它快生型根瘤菌。     

降血脂药物（DEHP）对酰基CoA氧化酶基因反式作用因子的影响

从对照和用ＤＥＨＰ处理的大鼠肝脏提取核蛋白,以含酰基ＣｏＡ氧化酶（ＡＯＸ）基因表达调控部位的ＤＮＡ片段和该基因的不同蛋白结合位点的ＤＮＡ片段作为核蛋白结合反应的探针,通过凝胶电泳迁移率改变实验和Ｓｏｕｔｈｗｅｓｔｅｒｎ印迹分析检查了ＤＥＨＰ对ＡＯＸ基因反式作用因子的影响。结果表明,降血脂药物ＤＥＨＰ可显著增加ＡＯＸ基因反式作用因子的含量和（或）与基因的结合活性,在转录水平上促进基因的表达。     

Molecular and statistical approaches to the detection and correction of errors in genotype databases.

Errors in genotyping data have been shown to have a significant effect on the estimation of recombination fractions in high-resolution genetic maps. Previous estimates of errors in existing databases have been limited to the analysis of relatively few markers and have suggested rates in the range 0.5%-1.5%. The present study capitalizes on the fact that within the Centre d'Etude du Polymorphisme Humain (CEPH) collection of reference families, 21 individuals are members of more than one family, with separate DNA samples provided by CEPH for each appearance of these individuals. By comparing the genotypes of these individuals in each of the families in which they occur, an estimated error rate of 1.4% was calculated for all loci in the version 4.0 CEPH database. Removing those individuals who were clearly identified by CEPH as appearing in more than one family resulted in a 3.0% error rate for the remaining samples, suggesting that some error checking of the identified repeated individuals may occur prior to data submission. An error rate of 3.0% for version 4.0 data was also obtained for four chromosome 5 markers that were retyped through the entire CEPH collection. The effects of these errors on a multipoint map were significant, with a total sex-averaged length of 36.09 cM with the errors, and 19.47 cM with the errors corrected. Several statistical approaches to detect and allow for errors during linkage analysis are presented. One method, which identified families containing possible errors on the basis of the impact on the maximum lod score, showed particular promise, especially when combined with the limited retyping of the identified families. The impact of the demonstrated error rate in an established genotype database on high-resolution mapping is significant, raising the question of the overall value of incorporating such existing data into new genetic maps.