Materials chemistry: macroporous crystalline vanadium oxide foam

Porous inorganic solids can be synthesized in complex forms, and here we describe a simple method to create an ultralight, macroporous, crystalline vanadium oxide foam by bubbling oxygen gas produced in situ through a viscous vanadium oxide gel. This foaming process could be extended to other metal oxides.     

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。     

一种用于结构动态过程数值模拟的广义有限元法

提出了一种能同时处理连续体和离散体动态过程的有限元法. 该法通过构造接触力模型, 将传统的离散元当做标准的一节点有限单元来看待. 新构造的一节点单元与常规有限单元具有同样物理特征, 包括应力和应变. 从而, 将离散元算法与有限元算法紧密结合在一起, 形成了统一的、与现有有限元系统兼容的广义有限元计算模型. 这种模型不仅简化了计算过程, 还可最大限度地发挥现有有限元代码的功能. 数值算例表明, 新方法可以更加有效地模拟大量离散体与连续体相互作用的复杂动力学过程.     

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。     

Mutations in genes encoding melanosomal proteins cause pigmentary glaucoma in DBA/2J mice.

Pigmentary glaucoma is a significant cause of human blindness. Abnormally liberated iris pigment and cell debris enter the ocular drainage structures, leading to increased intraocular pressure (IOP) and glaucoma. DBA/2J (D2) mice develop a form of pigmentary glaucoma involving iris pigment dispersion (IPD) and iris stromal atrophy (ISA). Using high-resolution mapping techniques, sequencing and functional genetic tests, we show that IPD and ISA result from mutations in related genes encoding melanosomal proteins. IPD is caused by a premature stop codon mutation in the Gpnmb (GpnmbR150X) gene, as proved by the occurrence of IPD only in D2 mice that are homozygous with respect to GpnmbR150X; otherwise, similar D2 mice that are not homozygous for GpnmbR150X do not develop IPD. ISA is caused by the recessive Tyrp1b mutant allele and rescued by the transgenic introduction of wildtype Tyrp1. We hypothesize that IPD and ISA alter melanosomes, allowing toxic intermediates of pigment production to leak from melanosomes, causing iris disease and subsequent pigmentary glaucoma. This is supported by the rescue of IPD and ISA in D2 eyes with substantially decreased pigment production. These data indicate that pigment production and mutant melanosomal protein genes may contribute to human pigmentary glaucoma. The fact that hypopigmentation profoundly alleviates the D2 disease indicates that therapeutic strategies designed to decrease pigment production may be beneficial in human pigmentary glaucoma.     

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.