Curvilinear, three-dimensional motion of chromatin domains and nucleoli in neuronal interphase nuclei

The term "nuclear rotation" refers to a motion of nucleoli within interphase nuclei of several cell types. No mechanism or function has been ascribed to this phenomenon, and it was unknown whether nuclear structures in addition to nucleoli participate in this motion. Moreover, it was unclear whether nuclear rotation occurs independent of concurrent motion of juxtanuclear cytoplasm. The work reported here presents quantitative evidence, for three-dimensional intranuclear, tandem motion of fluorescently labeled chromatin domains associated with nucleoli and those remote from nucleoli. The results show that such motion is curvilinear, that it is not restricted to nucleoli, and, moreover, that it occurs independently of motion of juxtanuclear, cytoplasmic structures. These results suggest that this motion represents karyoplasmic streaming and its function is to transpose to nuclear pores those chromatin domains actively transcribed.     

湖北省水稻生产动态演变的驱动力分析

本文在分析湖北省水稻生产动态演变的基础上,指出生产条件变化驱动、比较经济效益驱动、宏观政策变化驱动以及科学技术驱动是影响湖北省水稻生产变化的主要驱动力。     

Promoting the Middle East peace process by changing beliefs about group malleability

Four studies showed that beliefs about whether groups have a malleable versus fixed nature affected intergroup attitudes and willingness to compromise for peace. Using a nationwide sample (N = 500) of Israeli Jews, the first study showed that a belief that groups were malleable predicted positive attitudes toward Palestinians, which in turn predicted willingness to compromise. In the remaining three studies, experimentally inducing malleable versus fixed beliefs about groups among Israeli Jews (N = 76), Palestinian citizens of Israel (N = 59), and Palestinians in the West Bank (N = 53)--without mentioning the adversary--led to more positive attitudes toward the outgroup and, in turn, increased willingness to compromise for peace.     

关于高校体育教学中教学交往的缺失及其建构的探讨

在高校体育教学中,师生之间的良好交往是活跃课堂氛围和促进体育教学任务有效完成的重要保障。本文对当前我国高校体育教学中交往的特点进行了探讨,并分析了高校体育教学中交往缺失的原因,提出了构建高校体育教学交往的建议与策略,以期为高校体育教学效果的提高提供一些参考。     

农民专业合作组织发展的外部环境因素分析——对河南省农民专业合作组织的调查与思考

基于对河南省农民专业合作组织发展现状的调查,分析制约我国农民专业合作组织发展的外部因素,借鉴国际经验,探讨建立和发展我国农民专业合作组织的途径与方法。     

Deep-sea bacteria: isolation in the absence of decompression

Sampling and pure culture isolation of deep-sea bacteria without loss of in situ pressure is required in order to determine the viability of decompressionsensitive strains. This was achieved by using a pressure-retaining sterilizable seawater sampling system in connection with a prepressurized hyperbaric isolation chamber. Rates of growth and substrate uptake of the majority of isolates showed highly barotolerant characteristics, while the remainder (4 out of 15) exhibited barophilic characteristics.     

基于COM GIS的外部数据功能的探讨

在组件GIS的二次开发应用中,数据的输入与修改是一个重要且必须考虑的问题.以ESRI公司的MapObjects为例,其本身对数据修改、添加等功能的实现比较复杂,而采用外部数据则容易多了.该文针对这一问题,分析讨论了MO中外部数据访问功能的理论基础与实现方法,并在Visual C++6.0编程环境支持下,运用ADO技术,以Excel为例,组合MapObjects提供的图层关联、图层搜索、图层输出等功能,将Excel工作簿中的单张表按字段匹配添加至图层内,并按指定的图层名保存下来,从而高效、便捷、快速、灵活地输入GIS属性数据,体现了组件GIS强大的开发潜力,成为MO数据管理功能扩展的有益补充.     

Mosaic mutants: absence in a eucaryotic organism

Exposure of procaryotic and eucaryotic cells to mutagenic agents generally gives both complete mutants and mosaic mutants. Irradiation of the eucaryotic multicellular alga Ulva mutabilis with ultraviolet light has given exclusively complete mutants.     

Germ cell chimerism: absence in parabiotic frogs

Embryos of the leopard frog deprived of primordial germ cells by treatment with ultraviolet light were joined in parabiosis with normal, unirradiated embryos. The irradiated member of the pair was not colonized by germ cells from its normal partner. Unlike the primordial germ cells of birds and mammals, the germ cells of frog embryos are not carried by the circulating blood.     

Prolactin in the postpartum rat: synthesis and release in the absence of suckling stimulation

Postpartum female rats deprived of suckling stimulation while being kept continuously with pups nonetheless suspended ovarian cyclicity for an average of 16 days and responded to uterine trauma by forming deciduomata. These results show that the extramammary stimulation afforded by young is alone capable of sustaining prolactin output from the adenohypophysis of the postpartum rat.     

Collagen polypeptides: normal release from polysomes in the absence of proline hydroxylation

It is not necessary that proline be hydroxylated for the completion and release of nascent collagen chains from polysomes. Hydroxylation of collagen proline in vivo normally takes place predominantly on nascent polypeptides; however, in the presence of an inhibitor of hydroxylation, unhydroxylated chains are released. These chains may subsequently be hydroxylated when the inhibition is removed. The results clarify a controversy over the site of proline hydroxylation.     

Legumes symbioses: absence of Nod genes in photosynthetic bradyrhizobia

Leguminous plants (such as peas and soybeans) and rhizobial soil bacteria are symbiotic partners that communicate through molecular signaling pathways, resulting in the formation of nodules on legume roots and occasionally stems that house nitrogen-fixing bacteria. Nodule formation has been assumed to be exclusively initiated by the binding of bacterial, host-specific lipochito-oligosaccharidic Nod factors, encoded by the nodABC genes, to kinase-like receptors of the plant. Here we show by complete genome sequencing of two symbiotic, photosynthetic, Bradyrhizobium strains, BTAi1 and ORS278, that canonical nodABC genes and typical lipochito-oligosaccharidic Nod factors are not required for symbiosis in some legumes. Mutational analyses indicated that these unique rhizobia use an alternative pathway to initiate symbioses, where a purine derivative may play a key role in triggering nodule formation.     

Cholinesterase in plasma: first reported absence in the Bantu; half-life determination

A Bantu schoolgirl is the first non-Caucasoid found homozygous for the "silent" cholinesterase gene. Investigation of her family revealed two heterozygotes. The propositus possesses no antibody to normal cholinesterase. Transfused cholinesterase had in her a half-life of approximately 10 days.     

Glass hydration: a method of dating glass objects

A new nondestructive method for dating or authenticating man-made glass is proposed, and the initial results of an exploration of the potential of this method are presented. The method is based on a relation between the age of a glass object and the thickness of the layer of hydrated glass on its surface, with the thickness of this hydrated surface layer being measured by means of the (15)N nuclear resonance depth profiling technique. A qualitative age scale is established for some common 19th- and 20th-century American glass.