A cat cloned by nuclear transplantation

Sheep, mice, cattle, goats and pigs have all been cloned by transfer of a donor cell nucleus into an enucleated ovum, and now we add the successful cloning of a cat (Felis domesticus) to this list. However, this cloning technology may not be readily extendable to other mammalian species if our understanding of their reproductive processes is limited or if there are species-specific obstacles.     

数值学报（2003年第12卷）

本书是由英国剑桥大学出版、发行的不定期专题论文集，每年出版一卷，登载数值分析、计算方法及其应用等方面的高水平创造性研究论文或综述报告，论文作者多为当代相关领域的国际性学术带头人。     

作为非物质文化遗产的南涧彝族“跳菜”

本文根据衡量非物质文化遗产的四条标准：具有突出的历史、文化和科学价值；具有展现中华民族文化创造力的典型性和代表性；具有在一定群体中世代传承、活态存在的特点；具有鲜明特色，在当地有较大影响。结合南涧彝族“跳菜”的实际情况进行比照分析，得出了南涧彝族“跳菜”是一种非物质文化遗产的结论。     

The extent of linkage disequilibrium in Arabidopsis thaliana.

Linkage disequilibrium (LD), the nonrandom occurrence of alleles in haplotypes, has long been of interest to population geneticists. Recently, the rapidly increasing availability of genomic polymorphism data has fueled interest in LD as a tool for fine-scale mapping, in particular for human disease loci. The chromosomal extent of LD is crucial in this context, because it determines how dense a map must be for associations to be detected and, conversely, limits how finely loci may be mapped. Arabidopsis thaliana is expected to harbor unusually extensive LD because of its high degree of selfing. Several polymorphism studies have found very strong LD within individual loci, but also evidence of some recombination. Here we investigate the pattern of LD on a genomic scale and show that in global samples, LD decays within approximately 1 cM, or 250 kb. We also show that LD in local populations may be much stronger than that of global populations, presumably as a result of founder events. The combination of a relatively high level of polymorphism and extensive haplotype structure bodes well for developing a genome-wide LD map in A. thaliana.     

Galileo as a ‘bad theologian’: a formative myth about Galileo’s trial

For 150 years after Galileo’s condemnation in 1633, there were many references to the trial, but no sustained, heated or polarized discussions. Then came the thesis that Galileo was condemned not for being a good astronomer but for being a bad theologian (using Scripture to support astronomical hypotheses); it began in 1784–1785 with an apology of the Inquisition by Mallet du Pan in the Mercure de France and the printing in Tiraboschi’s Storia della letteratura italiana of an apocryphal letter attributed to Galileo but forged by Onorato Gaetani. This thesis is not only untenable and false but inverts and subverts the truth; it proved to be long-lasting and widely accepted; so it may be labeled a myth. It was held by such writers as Bergier; Bergier; B; Feller; Cooper; Purcell; Marini; Reumont; Madden and Duhem. Afterwards, it was generally abandoned, its death knell being pope John Paul II’s speeches in 1979–1992. The myth seems to have acted as a catalyst insofar as its creation encouraged the proliferation of pro-clerical accounts and the articulation of pro-Galilean ones, thus making the discussion of Galileo’s trial the cause célèbre it is today.     

早-中元古代Columbia超级大陆研究进展

地球在过去25亿年里曾发生过几次全球性大规模碰撞造山事件（如 Grenville事件,Pan-African事件等）;地质学家由此推测大陆块自早元古代以来曾发生过周期性拼合和分离,从而导致古超级大陆的形成和裂解[1].在过去10年里（1991～2001年）,被认为由约1.0 Ga Grenville造山事件所形成的超级大陆Rodinia已成为古大陆重建的一个热点[2,3].然而,地质学家们在重建Rodinia 过程中发现,并非全部Rodinia组成陆块都是由Grenville造山带所焊接,而     

基质金属蛋白酶-26(MMP-26)在小鼠胚胎植入过程中的作用

基质金属蛋白酶-26（MMP-26，又称Endometase或基质水解素-2）是MMPs家族的一个新成员，它可在胎盘，子宫以及不同肿瘤细胞系中表达，采用子宫角注射，免疫组化，原位杂交，胚泡与子宫上皮单层培养，免疫印迹，RT-PCR和RNA印迹等多种体内外实验方法研究并报道了MMP-26在小鼠胚胎中的表达以及MMP-26抗体在胚胎植入中的作用，研究表明，MMP-26的mRNA与蛋白在小鼠胚泡中均有强烈的表达，此外，体内研究显示，MMP-26抗体能显著抑制小鼠胚胎的着床；在体外培养体系中，MMP-26抗体可显著抑制小鼠胚泡在子宫上皮单层上的黏附与扩展；同时，MMP-26抗体以剂量依赖关系抑制整合素αV亚基mRNA和蛋白的表达，研究提示，MMP-26可能直接或间接参与滋养层细胞侵入子宫内膜的过程，促使小鼠胚泡成功植入。