Ethical Problem Solving and Systems Theory: The Complexity Connection

No matter what the present success in straightening out difficulties and harmonizing conflicts, it is certain that problems will recur in the future in a new form or on a different plane. Indeed, every genuine accomplishment instead of winding up an affair and enclosing it as a jewel in a casket for future contemplation complicates the practical situation. . . . From the side of what has gone before the achievement settles something. From the side of what comes after, it complicates, introducing new problems, unsettling factors. (John Dewey)     

织物起拱第一报:主观评价和心理物理标度

美观是消费者日常服装穿着功能中最重要的指标之一.起拱是一种外衣穿着中引起变化,令人不满的三维残余变形.一种主观评价方法是从一系列起拱织物的照片来理解心理物理学规律,采用优劣排序等级和优劣评判等级两种方法用于心理评价标度.这两种等级互相间紧密相关,但评判等级比排序等级包含更多的信息,可以更好地区分出两种织物间的差异.主观评价结果与测量得到的残余起拱高度之间线性相关,表明了织物起拱特性符合斯特藩指数定律.残余起拱高度对织物起拱特性总方差的贡献在94%以上.其它可能是起拱时各向异性因素引起的.     

虚拟社区的知识共享机制研究

虚拟社区是网民交流和获取知识的一个重要平台,知识共享能够给虚拟社区带来商业价值。本文基于社会交换理论分析了虚拟社区的知识共享过程及影响因素,构建了知识共享机制模型。     

A photic visual cycle of rhodopsin regeneration is dependent on Rgr.

During visual excitation, rhodopsin undergoes photoactivation and bleaches to opsin and all-trans-retinal. To regenerate rhodopsin and maintain normal visual sensitivity, the all-trans isomer must be metabolized and reisomerized to produce the chromophore 11-cis-retinal in biochemical steps that constitute the visual cycle and involve the retinal pigment epithelium (RPE; refs. 3-8). A key step in the visual cycle is isomerization of an all-trans retinoid to 11-cis-retinol in the RPE (refs. 9-11). It could be that the retinochrome-like opsins, peropsin, or the retinal G protein-coupled receptor (RGR) opsin12-16 are isomerases in the RPE. In contrast to visual pigments, RGR is bound predominantly to endogenous all-trans-retinal, and irradiation of RGR in vitro results in stereospecific conversion of the bound all-trans isomer to 11-cis-retinal. Here we show that RGR is involved in the formation of 11-cis-retinal in mice and functions in a light-dependent pathway of the rod visual cycle. Mutations in the human gene encoding RGR are associated with retinitis pigmentosa.     

Experimental study on photocount statistics of the ultraweak photon emission from some living organisms

The hypothesis that biophotons display a high degree of coherence was tested by measuring photocount statistics (PCS) of the ultraweak photon emission from three living organisms (cucumber seedling, mungbean seedling and soybean rhizobium bacteroids) with a high-sensitivity single-photon counter. For comparison, the same experiments were performed for laser beam, randomized laser beam, chemiluminescence from autoxidation of luminol and the dark counts of the equipment. Photocount distributions, close to Poissonian, were observed for the three tested biological systems but not for the pure chemiluminescence of luminol.     

浅议大跨度连续梁悬臂浇注的施工

随着大跨度连续梁的普及，混凝土悬臂浇注技术日趋成熟。文章较全面地介绍了挂篮施工的重点工序，包括墩项段O^n块、中间段、合拢段施工，并对挂篮施工中的几个重要参数的控制做了简要阐述。     

指纹识别技术在考试管理中的应用

指纹识别技术是一种成熟的生物识别技术，将指纹识别技术应用到考试管理中，通过指纹的唯一性和不可复制性，可有效杜绝考场上违法违纪现象的发生。介绍了指纹识别系统的选型、指纹识别系统的功能与特点以及软件设计的流程。     

Cell transformation and activation of pp60c-src by overexpression of a protein tyrosine phosphatase.

The kinase activity of pp60c-src is specifically and transiently increased during mitosis and repressed during interphase. Loss of cell-cycle control of pp60c-src occurs on mutation of Tyr527 to Phe or when pp60c-src is associated with polyoma middle-T-antigen, and these conditions result in cell transformation or tumorigenesis. In both cases, pp60c-src has elevated kinase activity which is maintained throughout the cell cycle and accompanied by dephosphorylation of the carboxy-terminal negative regulatory Tyr527 site, or mimicry of Tyr527 dephosphorylation in the case of the mutant. Here we report that overexpression of the receptor-like protein tyrosine phosphatase PTP alpha results in persistent activation of pp60c-src kinase, with concomitant cell transformation and tumorigenesis. In PTP alpha-overexpressing cells, the pp60c-src kinase activation is accompanied by dephosphorylation at Tyr527, and direct dephosphorylation of this site by purified PTP alpha occurs in vitro. Our results suggest that PTP alpha is involved in the regulation of cell proliferation, exerting at least some of its effects through pp60c-src kinase, and has oncogenic capability when overexpressed.     

A whole genome approach to in vivo DNA-protein interactions in E. coli.

The increasingly rapid pace at which genomic DNA sequences are being determined has created a need for more efficient techniques to determine which parts of these sequences are bound in vivo by the proteins controlling processes such as gene expression, DNA replication and chromosomal mechanics. Here we describe a whole-genome approach to identify and characterize such DNA sequences. The method uses endogenous or artificially introduced methylases to methylate all genomic targets except those protected in vivo by protein or non-protein factors interfering with methylase action. These protected targets remain unmethylated in purified genomic DNA and are identified using methylation-sensitive restriction endonucleases. When the method was applied to the Escherichia coli genome, 0.1% of the endogenous adenine methyl-transferase (Dam methylase) targets were found to be unmethylated. Five foreign methylases were examined by transfection. Database-matched DNA sequences flanking the in vivo-protected Dam sites all fell in the non-coding regions of seven E. coli operons (mtl, cdd, flh, gut, car, psp and fep). In the first four operons these DNA sequences closely matched the consensus sequence that binds to the cyclic AMP-receptor protein. The in vivo protection at the Dam site upstream of the car operon was correlated with a downregulation of car expression, as expected of a feedback repressor-binding model.