Unborn children (protection) bill

Enoch Powell's Unborn Children (Protection) Bill passed a second reading in the British House of Commons on 22 February 1985. The authors contend that most informed scientists are dismayed because, if enacted into law, the bill would criminalize the in vitro fertilization of any human oocytes except for purposes of "embryo insertion," and many promising avenues of research would be blocked. While the pro-life lobby maintains that the development of possible methods to cure genetic diseases does not require research on human embryos, Evans and McLaren cite scientific data to argue that such research is necessary to insure that embryos chosen for implantation are chromosomally normal, to study the etiology of chromosomal disorders and eventually develop therapies for them, to improve IVF procedures, and to develop new contraceptive techniques.     

英国议会与法国三级会议不同历史命运的对比

中世纪,英国与法国的等级代表权力机关———议会与三级会议产生后出现了截然不同的命运,这是因为英国议会是人民斗争、限制王权的结果,而法国的三级会议却是王权加强的需要和结果,议会和三级会议本身就有许多的不同。此外,英法两国不同的政治传统、中世纪末期不同的政治发展趋向以及百年战争、宗教改革等重大历史事件对两国的不同影响也是导致两者不同命运的重要因素。     

IVF: regulation or prohibition?

Britain's Parliament soon will vote on the Human Fertilisation and Embryology Bill and the outcome will have a major impact on in vitro fertilization (IVF) research in that country. The bill would set up a Statutory Licensing Authority to oversee IVF and other reproductive technologies and to license IVF research projects, unless Parliament votes to ban and criminalize such research. McLaren describes the benefits that can be expected from allowing licensed IVF research, and counters arguments for its prohibition. She urges scientists to make their positions on the upcoming vote clear to their Members of Parliament.     

《关于费尔巴哈的提纲》第三条及其修改述评——纪念马克思逝世130周年

在《关于费尔巴哈的提纲》第三条中，马克思基于新的实践唯物主义立场，剖析了18世纪法国唯物主义哲学历史观的两大理论缺陷，揭示了实践是环境、教育及人自身形成与改变的共同根基。恩格斯所做的四处修改，没有改变马克思的原则立场和根本观点，但的确存在内容表述的不同和一定程度的思想差异，效果有利有弊。回归马克思稿本，有利于展现第三条的思想原韵。     

Embryo research: British Commons vote for ban

The British House of Commons, overriding opposition by party leaders, approved Enoch Powell's bill which would ban all experiments on human embryos and restrict their use to therapeutic in vitro fertilization procedures. Some members of Parliament have urged the government to announce a timetable for its own, more comprehensive legislation based on the recommendations of the Warnock Committee Report. This action would erode support for Powell's bill, which Lady Warnock warns could end in vitro fertilization in Britain.     

Gene manipulation watchdog: too smooth?

The continued existence of Britain's Genetic Manipulation Advisory Group (GMAG) may be threatened by its low-key success in regulating that country's research in genetic engineering. Most responsibility for evaluating safety conditions in existing facilities now rests with in-house committees. GMAG mainly drafts guidance notes on containment and assesses the safety standards of laboratories just beginning to do genetic research, functions which some feel could be handled by other government bodies. Industry and academics disagree on whether its continued existence is warranted; Parliament is expected to make the decision by the end of the year.     

The SIL gene is required for mouse embryonic axial development and left-right specification.

The establishment of the main body axis and the determination of left-right asymmetry are fundamental aspects of vertebrate embryonic development. A link between these processes has been revealed by the frequent finding of midline defects in humans with left-right anomalies. This association is also seen in a number of mutations in mouse and zebrafish, and in experimentally manipulated Xenopus embryos. However, the severity of laterality defects accompanying abnormal midline development varies, and the molecular basis for this variation is unknown. Here we show that mouse embryos lacking the early-response gene SIL have axial midline defects, a block in midline Sonic hedgehog (Shh) signalling and randomized cardiac looping. Comparison with Shh mutant embryos, which have axial defects but normal cardiac looping, indicates that the consequences of abnormal midline development for left-right patterning depend on the time of onset, duration and severity of disruption of the normal asymmetric patterns of expression of nodal, lefty-2 and Pitx2.     

一场被神化的革命——我们应该有怎样的法国大革命史观

长期以来我们给了法国大革命很多溢美之词，忽视了法国大革命所带来的许多负面效应，其实法国大革命是一场被神化了的革命。大革命期间最不能容忍的行为就是所谓的革命恐怖活动。启蒙运动为法国大革命提供了思想上、理论上的准备，但是法国启蒙运动思想家的理论不仅存在着巨大的缺陷和难以实现，而且一旦实施必将出现混乱和灾难。法国大革命留下了严重的社会后遗症，现在到了把法国大革命从神圣的祭台上撤下来的时候了。     

浅析银行营业厅服务质量的优化

随着市场的不断变化,顾客的需求层出不穷,服务的追求也永无止境。目前,中国的银行业务进入了一个以投资理财、消费服务为特征的新阶段,新阶段带来的新变化对我国金融业的发展和服务提出了更高的要求和更多的期待。阐述了银行营业厅服务质量与顾客满意度的现状,探讨了银行营业厅服务存在的问题,提出了优化银行营业厅服务质量的策略。     

微注射人TCP10L基因对斑马鱼形态的影响

利用模式生物斑马鱼,通过微注射的方法,研究了人肝脏特异性转录因子TCP10L对斑马鱼早期胚胎发育的影响.结果显示:人TCP10L基因对斑马鱼胚胎发育有一定的毒性.表现为早期的脊索发育异常,个体严重畸形;当血液循环出现后,表现为血流延缓和围心腔水肿等症状.该项研究表明:人肝脏特异性转录因子TCP10L在斑马鱼胚胎中的过表达会引起显著的形态异常和心血管障碍,并且这种影响与其是否在斑马鱼肝内的特异表达有关,为进一步探明该转录因子在人肝脏内发挥的功能奠定了基础.     

某高层图书馆处方式与性能化设计对防排烟效果的研究

针对某高层图书馆的防排烟系统分别进行处方式设计和性能化设计,运用FDS软件模拟各设计方案,通过对单层设计和整栋设计中温度、能见度、CO浓度等参数的变化规律的模拟,对比分析处方式设计和性能化设计对防排烟的影响。通过模拟与数据分析得出,走道增设防火卷帘能在一定程度上阻碍烟雾向前室与防烟楼梯间的蔓延速度,合理设置前室与防烟楼梯间的正压送风量效果要优于楼梯间单独加压送风(送风量比前者大)的防烟效果。     

Dishevelled controls cell polarity during Xenopus gastrulation

Although cell movements are vital for establishing the normal architecture of embryos, it is unclear how these movements are regulated during development in vertebrates. Inhibition of Xenopus Dishevelled (Xdsh) function disrupts convergent extension movements of cells during gastrulation, but the mechanism of this effect is unclear, as cell fates are not affected. In Drosophila, Dishevelled controls both cell fate and cell polarity, but whether Dishevelled is involved in controlling cell polarity in vertebrate embryos has not been investigated. Here we show, using time-lapse confocal microscopy, that the failure of cells lacking Xdsh function to undergo convergent extension results from defects in cell polarity. Furthermore, Xdsh mutations that inhibit convergent extension correspond to mutations in Drosophila Dishevelled that selectively perturb planar cell polarity. Finally, the localization of Xdsh at the membrane of normal dorsal mesodermal cells is consistent with Xdsh controlling cell polarity. Our results show that polarized cell behaviour is essential for convergent extension and is controlled by vertebrate Dishevelled. Thus, a vertebrate equivalent of the Drosophila planar cell polarity signalling cascade may be required for normal gastrulation.     

Deletion of brain dystroglycan recapitulates aspects of congenital muscular dystrophy

Fukuyama congenital muscular dystrophy (FCMD), muscle-eye-brain disease (MEB), and Walker-Warburg syndrome are congenital muscular dystrophies (CMDs) with associated developmental brain defects. Mutations reported in genes of FCMD and MEB patients suggest that the genes may be involved in protein glycosylation. Dystroglycan is a highly glycosylated component of the muscle dystrophin-glycoprotein complex that is also expressed in brain, where its function is unknown. Here we show that brain-selective deletion of dystroglycan in mice is sufficient to cause CMD-like brain malformations, including disarray of cerebral cortical layering, fusion of cerebral hemispheres and cerebellar folia, and aberrant migration of granule cells. Dystroglycan-null brain loses its high-affinity binding to the extracellular matrix protein laminin, and shows discontinuities in the pial surface basal lamina (glia limitans) that probably underlie the neuronal migration errors. Furthermore, mutant mice have severely blunted hippocampal long-term potentiation with electrophysiologic characterization indicating that dystroglycan might have a postsynaptic role in learning and memory. Our data strongly support the hypothesis that defects in dystroglycan are central to the pathogenesis of structural and functional brain abnormalities seen in CMD.     

Intracardiac fluid forces are an essential epigenetic factor for embryonic cardiogenesis

The pattern of blood flow in the developing heart has long been proposed to play a significant role in cardiac morphogenesis. In response to flow-induced forces, cultured cardiac endothelial cells rearrange their cytoskeletal structure and change their gene expression profiles. To link such in vitro data to the intact heart, we performed quantitative in vivo analyses of intracardiac flow forces in zebrafish embryos. Using in vivo imaging, here we show the presence of high-shear, vortical flow at two key stages in the developing heart, and predict flow-induced forces much greater than might have been expected for micro-scale structures at low Reynolds numbers. To test the relevance of these shear forces in vivo, flow was occluded at either the cardiac inflow or outflow tracts, resulting in hearts with an abnormal third chamber, diminished looping and impaired valve formation. The similarity of these defects to those observed in some congenital heart diseases argues for the importance of intracardiac haemodynamics as a key epigenetic factor in embryonic cardiogenesis.     

Limits on bilingualism

Speech, in any language, is continuous; speakers provide few reliable cues to the boundaries of words, phrases, or ther meaningful units. To understand speech, listeners must divide the continuous speech stream into portions that correspond to such units. This segmentation process is so basic to human language comprehension that psycholinguists long assumed that all speakers would do it in the same way. In previous research, however, we reported that segmentation routines can be language-specific: speakers of English do not. French has relatively clear syllable boundaries and syllable-based timing patterns, whereas English has relatively unclear syllable boundaries and stress-based timing; thus syllabic segmentation would work more efficiently in the comprehension of French than in the comprehension of English. Our present study suggests that at this level of language processing, there are limits to bilingualism: a bilingual speaker has one and only one basic language.     

高校法语教学的弊端及对策

随着经济全球化的发展,中国与法语国家之间的交流日益频繁,法语越来越多地被运用到社会生活中。在我国,法语人才奇缺已成为不争的事实。而我国高校的法语教学大多采用传统的"填鸭式"方法,即教师将教学重点放在词汇和语法上,致使培养出来的法语专业本科生大部分听说能力较差,很难适应对外交流的需要。针对此种现象,提出改进法语教学的对策,旨在引起法语教学与教研工作者的注意。     

斑马鱼胚胎发育的功能染色体组

随着人类和其他物种染色体组测序工作的完成 ,人类科学最大的任务就是阐明数以万计的基因的生物功能。人类和动物生命周期都从受精卵开始 ,然后一步一步地发育成具有多元组织和器官的生物体。在胚胎形成过程中 ,伴随着基因生成物的协同运作 ,基因按其固有的程序陆续显现出影响 ,从而决定并实现整个人体程序。如果使用适当的动物做模型的话 ,可以加速胚胎功能染色体组的研究。斑马鱼就是这项研究一个很好的模型。斑马鱼最大的优点就是产卵多、体外胚胎发育、体积小、容易养活 ,除此以外 ,很多的分子、细胞、胚胎和基因操作在斑马鱼身上都很容…     

Embryonic and extraembryonic stem cell lines derived from single mouse blastomeres

The most basic objection to human embryonic stem (ES) cell research is rooted in the fact that ES cell derivation deprives embryos of any further potential to develop into a complete human being. ES cell lines are conventionally isolated from the inner cell mass of blastocysts and, in a few instances, from cleavage stage embryos. So far, there have been no reports in the literature of stem cell lines derived using an approach that does not require embryo destruction. Here we report an alternative method of establishing ES cell lines-using a technique of single-cell embryo biopsy similar to that used in pre-implantation genetic diagnosis of genetic defects-that does not interfere with the developmental potential of embryos. Five putative ES and seven trophoblast stem (TS) cell lines were produced from single blastomeres, which maintained normal karyotype and markers of pluripotency or TS cells for up to more than 50 passages. The ES cells differentiated into derivatives of all three germ layers in vitro and in teratomas, and showed germ line transmission. Single-blastomere-biopsied embryos developed to term without a reduction in their developmental capacity. The ability to generate human ES cells without the destruction of ex utero embryos would reduce or eliminate the ethical concerns of many.     

法、汉语篇中替代类型之对比研究

通过比较法、汉语篇中三种主要的替代类型:名词替代、动词替代和小句替代,可以发现替代的确是汉语的一种衔接手段,而非为英语法语所独有。