Iridophore development in wild-type and periodic albinoXenopus larvae

Summary Light microscopic studies of iridophore preparations from a^p mutantXenopus larvae revealed abnormalities in the morphology and size distribution of reflecting platelets; purine synthesis is normal. A pleiotropic effect of the a^p gene on melanoblasts and iridoblasts is proposed.     

Constructing dissimilarity measures

The paper addresses the problem of specifying differential weights for variables in the construction of a measure of dissimilarity. An assessor is required to provide subjective judgments of the pairwise dissimilarities within a training set of objects, and these dissimilarities are then modeled as a function of the recorded differences between the objects on each of the variables. The aim is to make explicit the relative importance that assessors attach to each of the variables, and thus obtain guidance on how these variables should be combined into a relevant dissimilarity matrix. The methodology is illustrated by application to some archaeological data.     

教育学习工具灵活和有效的瘦客户部署方式

Given today's dynamic and fast paced world of Information Technology(IT),it has become more challenging for an IT manager to provide students with the most flexible and innovative learning environment.The requirement to provide these facilities must be balanced against constraints such as capital spending within budgets,maintenance costs and staffing issues.This paper discusses how a server-centric IT solution,such as thin clients,is capable of meeting these demands in a more efficient manner particularly in relation to Financial Management,Infrastructure Management and Security Management.The flexibility and efficiency of server-centric technology as an education tool is overviewed as experienced by several departments within the Dublin Institute of Technology.     

Mutation of TBCE causes hypoparathyroidism-retardation-dysmorphism and autosomal recessive Kenny-Caffey syndrome

The syndrome of congenital hypoparathyroidism, mental retardation, facial dysmorphism and extreme growth failure (HRD or Sanjad-Sakati syndrome; OMIM 241410) is an autosomal recessive disorder reported almost exclusively in Middle Eastern populations. A similar syndrome with the additional features of osteosclerosis and recurrent bacterial infections has been classified as autosomal recessive Kenny-Caffey syndrome (AR-KCS; OMIM 244460). Both traits have previously been mapped to chromosome 1q43-44 (refs 5,6) and, despite the observed clinical variability, share an ancestral haplotype, suggesting a common founder mutation. We describe refinement of the critical region to an interval of roughly 230 kb and identification of deletion and truncation mutations of TBCE in affected individuals. The gene TBCE encodes one of several chaperone proteins required for the proper folding of alpha-tubulin subunits and the formation of alpha-beta-tubulin heterodimers. Analysis of diseased fibroblasts and lymphoblastoid cells showed lower microtubule density at the microtubule-organizing center (MTOC) and perturbed microtubule polarity in diseased cells. Immunofluorescence and ultrastructural studies showed disturbances in subcellular organelles that require microtubules for membrane trafficking, such as the Golgi and late endosomal compartments. These findings demonstrate that HRD and AR-KCS are chaperone diseases caused by a genetic defect in the tubulin assembly pathway, and establish a potential connection between tubulin physiology and the development of the parathyroid.     

科学素质促进人类社会可持续发展

 如何利用科学素质,让人类更好地实现促进可持续发展这一目标,是一个值得思考的问题。可持续发展,即人类不仅有能力确保当前需求得到满足,而且不会影响到未来的需求。这样一种将过去与未来相连的概念,需要更深刻地理解这个问题,科学、技术和社会如何能够共同发挥作用,彼此互补,使三者在未来实现和谐发展、相互促进。同时也需要了解社会、经济、技术、科学和环境等问题之间的相互关系。把未来和现在进行关联是一项非常大的挑战,科学素质是其中一个很重要的问题,如何让人们了解科学素质与人类可持续发展的关系,怎样把未来和过去相联接,需要在决策中体现出来。